Using a mouse this problem started happening in the past week or 2 for me.
When middle button emulation is ticked, if you drag the timeout slider to the longest time, release, and try to drag it back to the shortest time, the cursor will not click down until a second or 2 after you clicked down with your mouse, and the cursor will begin clicking where-ever the cursor was after that delay.
It causes another problem which is the main problem for me: I keep the timeout setting to the shortest as that's all I need to click both buttons to simulate a middle click. However, when using left click and holding it down (e.g. to highlight text) it now sometimes 'glitches' and the system thinks I let go of the left mouse button even when I didn't. The same thing happens if I switch left and right click so I'm holding right mouse button drag in accessibility settings. This causes my highlight selection to get reset and start highlighting again from where it glitched.
This glitching seems to be solved or at least non-apparent when I uncheck the 'use middle mouse button emulation' checkbox.
I also notice sometimes the left mouse click doesn't work - it doesn't actually click.
Configuration:
I'm running Kubuntu 14.04 LTS 64bit
Linux 3.16.0-38-generic #52~14.04.1-Ubuntu SMP
gpointing-device-settings is at 1.5.1-6ubuntu2 same version for the past few months/year
I have not changed the gpointing-device-settings package in the last few weeks, while I think this problem started occurring in the past week (in June), so it may be related to upstream package changes. This is my apt history for the last couple of weeks (/var/log/apt/history.log):
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Start-Date: 2015-05-23 07:42:04
Upgrade: virtualbox:amd64 (4.3.10-dfsg-1ubuntu4, 4.3.10-dfsg-1ubuntu5), virtualbox-dkms:amd64 (4.3.10-dfsg-1ubuntu4, 4.3.10-dfsg-1ubuntu5), virtualbox-qt:amd64 (4.3.10-dfsg-1ubuntu4, 4.3.10-dfsg-1ubuntu5)
End-Date: 2015-05-23 07:45:19
Start-Date: 2015-05-25 17:43:46
Commandline: apt-get install padre
Install: libclass-adapter-perl:amd64 (1.07-1, automatic), libaliased-perl:amd64 (0.31-1, automatic), libclass-unload-perl:amd64 (0.08-1, automatic), libfile-pushd-perl:amd64 (1.005-1, automatic), libmodule-metadata-perl:amd64 (1.000019-1, automatic), libparams-util-perl:amd64 (1.07-1build1, automatic), libpadwalker-perl:amd64 (1.98-1, automatic), libcpan-meta-requirements-perl:amd64 (2.125-1, automatic), libdevel-refactor-perl:amd64 (0.05-1, automatic), cpanminus:amd64 (1.7001-1, automatic), libclass-xsaccessor-perl:amd64 (1.19-1build1, automatic), libtext-findindent-perl:amd64 (0.10-1, automatic), libwx-perl:amd64 (0.9922-2, automatic), libcpan-distnameinfo-perl:amd64 (0.12-1, automatic), libwxbase2.8-dev:amd64 (2.8.12.1+dfsg-2ubuntu2, automatic), liborlite-perl:amd64 (1.98-1, automatic), libfile-homedir-perl:amd64 (1.00-1, automatic), libwx-perl-processstream-perl:amd64 (0.32-1, automatic), libwxgtk2.8-dev:amd64 (2.8.12.1+dfsg-2ubuntu2, automatic), libfile-slurp-perl:amd64 (9999.19-4, automatic), libtext-patch-perl:amd64 (1.8-1, automatic), ack-grep:amd64 (2.12-1, automatic), liblocal-lib-perl:amd64 (1.008023-1, automatic), libppi-perl:amd64 (1.215-1, automatic), wx2.8-headers:amd64 (2.8.12.1+dfsg-2ubuntu2, automatic), libparse-errorstring-perl-perl:amd64 (0.19-1, automatic), libterm-readline-gnu-perl:amd64 (1.20-2build2, automatic), libnumber-compare-perl:amd64 (0.03-1, automatic), libdevel-dumpvar-perl:amd64 (1.06-1, automatic), liborlite-migrate-perl:amd64 (1.10-1, automatic), libfile-find-rule-perl:amd64 (0.33-1, automatic), libpod-pom-perl:amd64 (0.29-1, automatic), libyaml-tiny-perl:amd64 (1.56-1, automatic), libtask-weaken-perl:amd64 (1.04-1, automatic), liblocale-msgfmt-perl:amd64 (0.15-1, automatic), libppix-regexp-perl:amd64 (0.036-1, automatic), libdebug-client-perl:amd64 (0.29-1, automatic), libio-socket-ip-perl:amd64 (0.25-3, automatic), libppix-editortools-perl:amd64 (0.18-1, automatic), libwxgtk-media2.8-dev:amd64 (2.8.12.1+dfsg-2ubuntu2, automatic), libclass-inspector-perl:amd64 (1.28-1, automatic), libalien-wxwidgets-perl:amd64 (0.64+dfsg-2, automatic), libpath-class-perl:amd64 (0.33-1, automatic), libcpan-meta-perl:amd64 (2.133380-2, automatic), libcpan-meta-check-perl:amd64 (0.007-1, automatic), libipc-run3-perl:amd64 (0.046-1, automatic), libtext-glob-perl:amd64 (0.09-1, automatic), libfile-next-perl:amd64 (1.12-1, automatic), libfile-which-perl:amd64 (1.09-1, automatic), libfile-remove-perl:amd64 (1.52-1, automatic), libpod2-base-perl:amd64 (0.043-1, automatic), libwx-scintilla-perl:amd64 (0.38-1build1, automatic), libtext-diff-perl:amd64 (1.41-1, automatic), libcapture-tiny-perl:amd64 (0.24-1, automatic), libfile-sharedir-perl:amd64 (1.03-1, automatic), libsort-versions-perl:amd64 (1.5-4, automatic), libstring-shellquote-perl:amd64 (1.03-1, automatic), libmodule-cpanfile-perl:amd64 (1.0002-1, automatic), libtemplate-tiny-perl:amd64 (1.12-1, automatic), libpod-abstract-perl:amd64 (0.20-1, automatic), padre:amd64 (1.00+dfsg-1), libparse-exuberantctags-perl:amd64 (1.01-1build3, automatic), libprobe-perl-perl:amd64 (0.03-1, automatic), libparse-cpan-meta-perl:amd64 (1.4409-1, automatic), libmodule-manifest-perl:amd64 (1.08-1, automatic), libmodule-starter-perl:amd64 (1.620+dfsg-1, automatic)
End-Date: 2015-05-25 17:45:04
Start-Date: 2015-05-27 07:51:50
Upgrade: libldap2-dev:amd64 (2.4.31-1+nmu2ubuntu8, 2.4.31-1+nmu2ubuntu8.1), libldap-2.4-2:amd64 (2.4.31-1+nmu2ubuntu8, 2.4.31-1+nmu2ubuntu8.1), libldap-2.4-2:i386 (2.4.31-1+nmu2ubuntu8, 2.4.31-1+nmu2ubuntu8.1)
End-Date: 2015-05-27 07:51:59
Start-Date: 2015-06-01 17:15:55
Commandline: apt-get install jpegoptim
Install: jpegoptim:amd64 (1.3.0-1ubuntu1)
End-Date: 2015-06-01 17:16:13
Start-Date: 2015-06-02 07:44:49
Upgrade: libssl1.0.0:amd64 (1.0.1f-1ubuntu2.11, 1.0.1f-1ubuntu2.12), libssl1.0.0:i386 (1.0.1f-1ubuntu2.11, 1.0.1f-1ubuntu2.12), libssl-dev:amd64 (1.0.1f-1ubuntu2.11, 1.0.1f-1ubuntu2.12), libssl-doc:amd64 (1.0.1f-1ubuntu2.11, 1.0.1f-1ubuntu2.12), openssl:amd64 (1.0.1f-1ubuntu2.11, 1.0.1f-1ubuntu2.12)
End-Date: 2015-06-02 07:45:06
Start-Date: 2015-06-04 08:04:51
Upgrade: libqt5concurrent5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), qt5-qmake:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-xml:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-xml:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-network:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-network:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-sql-mysql:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-sql-mysql:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), qt5-default:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-sql:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-sql:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5sql5-sqlite:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt5opengl5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), qdbus:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtcore4:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtcore4:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-qt3support:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), t1utils:amd64 (1.37-2ubuntu1, 1.37-2ubuntu1.1), libqt4-svg:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-dbus:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-dbus:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-xmlpatterns:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-xmlpatterns:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-sql-sqlite:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-opengl:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-opengl:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), qtbase5-dev-tools:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-script:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-script:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5sql5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt5core5a:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-opengl-dev:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-dev-bin:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), qt4-linguist-tools:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5xml5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt5test5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-designer:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5printsupport5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), qtcore4-l10n:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtdbus4:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtdbus4:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5opengl5-dev:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-test:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5widgets5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-scripttools:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-dbg:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5dbus5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-dev:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt5gui5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt5network5:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), qt4-qmake:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtgui4:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqtgui4:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-declarative:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), libqt4-declarative:i386 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1), qtbase5-dev:amd64 (5.2.1+dfsg-1ubuntu14.2, 5.2.1+dfsg-1ubuntu14.3), libqt4-help:amd64 (4.8.5+git192-g085f851+dfsg-2ubuntu4, 4.8.5+git192-g085f851+dfsg-2ubuntu4.1)
End-Date: 2015-06-04 08:06:37
Start-Date: 2015-06-06 12:42:11
Commandline: apt-get install vim
Install: vim:amd64 (7.4.052-1ubuntu3), vim-runtime:amd64 (7.4.052-1ubuntu3, automatic)
End-Date: 2015-06-06 12:42:34
Start-Date: 2015-06-07 16:01:21
Commandline: apt-get install dconf-editor
Install: dconf-editor:amd64 (0.20.0-1)
End-Date: 2015-06-07 16:01:41
Start-Date: 2015-06-07 16:12:07
Commandline: apt-get install gnome-settings-daemon
Install: gnome-settings-daemon:amd64 (3.8.6.1-0ubuntu11.2), nautilus-data:amd64 (3.10.1-0ubuntu9.8, automatic), libwacom-common:amd64 (0.8-1, automatic), libwacom2:amd64 (0.8-1, automatic), gnome-settings-daemon-schemas:amd64 (3.8.6.1-0ubuntu11.2, automatic)
End-Date: 2015-06-07 16:13:26
I'd be happy with a workaround just to be productive on my main system, I tried stuff on this thread: http://
Tried to use gsettings but it didn't work for me, synclient doesn't work because I'm using a mouse.