Language translation of the messages

have you tried to run in a terminal "LANG=locale gwibber", where locale is your localization (ru_RU?)

lprof@uno:~$ LANG=ru_RU gwibber

(process:4907): Gtk-WARNING **: Locale not supported by C library.
 Using the fallback 'C' locale.

** (gwibber:4907): WARNING **: Trying to register gtype 'WnckWindowState' as enum when in fact it is of type 'GFlags'

** (gwibber:4907): WARNING **: Trying to register gtype 'WnckWindowActions' as enum when in fact it is of type 'GFlags'

** (gwibber:4907): WARNING **: Trying to register gtype 'WnckWindowMoveResizeMask' as enum when in fact it is of type 'GFlags'

I forgot mention that you need have installed ru_RU locales in your system (you should go to System->Administration->Language Support to do it)

Regards

Russian language is already installed http://dl.dropbox.com/u/586814/lang2.png
lprof@uno:~$ locale -a
C
en_AG
en_AG.utf8
en_AU.utf8
en_BW.utf8
en_CA.utf8
en_DK.utf8
en_GB.utf8
en_HK.utf8
en_IE.utf8
en_IN
en_IN.utf8
en_NG
en_NG.utf8
en_NZ.utf8
en_PH.utf8
en_SG.utf8
en_US.utf8
en_ZA.utf8
en_ZW.utf8
POSIX
ru_RU.utf8
ru_UA.utf8
zh_CN.utf8
zh_SG.utf8

so, if you ran in a terminal "$LANG=ru_RU gwibber" what happens? Please could you attach an screenshot of this problem?

http://dl.dropbox.com/u/586814/uno.png
It seems that the problem is locale ru_RU is POSIX and not included in the С library