Several extensions doesn't work with Chromium

[Artyom Aleksyuk]

I recently discovered that TamperMonkey extension doesn't work with Chromium 29.0.1547.65-0ubuntu2 from an Ubuntu repository, however it works perfectly with Chrome 30.0.1599.66-1 from Google stable repository.
A bug occurs with both my usual profile and a fresh one (created via "chromium-browser --temp-profile").
Another extensions which doesn't work is VkOpt. Native UserScripts are not working too. Both VkOpt, UserScripts and TamperMonkey are modifying a content of a page. Other extensions works fine.
I have used this extensions for ages and they certainly work with Chromium.
To check this bug, please follow this steps:
1) Install TamperMonkey from a Google extensions store.
2) Install any extension from http://userscripts.org/
3) Check if pages are (not) being modified.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: chromium-browser 29.0.1547.65-0ubuntu2
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
Date: Sat Oct 12 22:28:27 2013
Desktop-Session:
 DESKTOP_SESSION = kde-plasma
 XDG_CONFIG_DIRS = /etc/xdg/xdg-kde-plasma:/usr/share/upstart/xdg:/etc/xdg
 XDG_DATA_DIRS = /usr/share:/usr/share/kde-plasma:/usr/local/share/:/usr/share/
DetectedPlugins:
 => Chromoting Viewer
    - enabled = True
    - path = internal-remoting-viewer
 => Chromoting Viewer
    - enabled = True
Env:
 MOZ_PLUGIN_PATH = None
 LD_LIBRARY_PATH = None
InstallationDate: Installed on 2013-09-27 (15 days ago)
InstallationMedia: Kubuntu 13.10 "Saucy Salamander" - Beta amd64 (20130925.1)
MarkForUpload: True
SourcePackage: chromium-browser
UpgradeStatus: No upgrade log present (probably fresh install)
chromium-default: CHROMIUM_FLAGS=""
gconf-keys: /desktop/gnome/applications/browser/exec = b'firefox\n'/desktop/gnome/url-handlers/https/command = b'sensible-browser %s\n'/desktop/gnome/url-handlers/https/enabled = b'true\n'/desktop/gnome/url-handlers/http/command = b'sensible-browser %s\n'/desktop/gnome/url-handlers/http/enabled = b'true\n'/desktop/gnome/session/required_components/windowmanager = b''/apps/metacity/general/compositing_manager = b''/desktop/gnome/interface/icon_theme = b'gnome\n'/desktop/gnome/interface/gtk_theme = b'Clearlooks\n'

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.