Clicking on Intuos4 medium tablet buttons breaks brush movement in GIMP 2.8.2. and MyPaint 1.0.0

[phukariflux]

Tablet buttons are default (not configured at all)

For GIMP:

1) set stylus, eraser, cursor and pad to screen mode

2) draw a line with brush, notice success

3) start drawing a line and press one of the 8 buttons on Intuos4, brush movement stops immediately

4) if stylus mode is set to relative mode via command *xsetwacom set "Wacom Intuos4 6x9 stylus" mode "Relative"* and one of the 8 buttons on Intuos4 is pressed then the pressure sensitivity will stop working properly also (brush will constantly look same as if it was pressed down hard)

For MyPaint (problem only in relative mode):

1) pen input is set to screen mode

2) stylus mode is set to relative mode via command *xsetwacom set "Wacom Intuos4 6x9 stylus" mode "Relative"*

3) start drawing a line and press one of the 8 buttons on Intuos4, the brush sensitivity will break immediately (brush will look as if it was pressed down hard); brush is also "stuck" (meaning: won't stop drawing on the screen even if stylus does not touch the Intuos4 surface anymore)

Also while stylus is set to relative mode, once the bug is triggered in gimp it will "carry on" to mypaint and vice-versa (broken sens in gimp <--> broken sens + "stuck" in mypaint) and I can only stop it if I click on desktop background with my mouse.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: xserver-xorg-input-wacom 1:0.17.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-19.30-generic 3.5.7
Uname: Linux 3.5.0-19-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.6.1-0ubuntu6
Architecture: amd64
Date: Wed Dec 12 22:19:50 2012
InstallationDate: Installed on 2012-11-28 (14 days ago)
InstallationMedia: Xubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.1)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xf86-input-wacom
UpgradeStatus: No upgrade log present (probably fresh install)