VNC produces extra, false characters when I type on the keyboard. The most common false characters are '2' after '"', and ',' after '|'. That is, if I type shift-2 for '"', I get a '2' after it. Seems that the problem is in key repetition: If I press shift, '2', and release the shift before '2', I immediately get '"2'. The same goes for '|', if I release altgr before '<', I get '|,' and sometimes the ',' tends to get stuck, so I get '|,,,,,,,,,,,,'... until I hit another button.

I suffered from this bug as early as SuSE 9.2 times. That time I resolved it by compiling tightvnc from original source. I haven't tested what happens if I compile the tightvnc from OpenSuse source.rpm.

To reproduce, at least this way I have hit the bug in two different computers:

Update SuSE 9.2 PRO to OpenSuse 10.0: select http://ftp.linux.ee/pub/suse/opensuse/inst-source as installation source,
Update System. Boot to X, create vncserver, vncviewer localhost:1, the xterm
should open automatically, in that xterm try shift down - 2 down - shift up - 
and you should get '"2'.

Keyboard finnish, < in between left shift and Z. 
archy@spirjr:~> locale
LANG=en_US
LC_CTYPE="en_US"
LC_NUMERIC="en_US"
LC_TIME="en_US"
LC_COLLATE="en_US"
LC_MONETARY="en_US"
LC_MESSAGES="en_US"
LC_PAPER="en_US"
LC_NAME="en_US"
LC_ADDRESS="en_US"
LC_TELEPHONE="en_US"
LC_MEASUREMENT="en_US"
LC_IDENTIFICATION="en_US"
LC_ALL=
archy@spirjr:~> uname -a
Linux spirjr 2.6.13-15-default #1 Tue Sep 13 14:56:15 UTC 2005 i686 i686 i386 GNU/Linux
archy@spirjr:~> rpm -qa|grep vnc
tightvnc-1.2.9-186
xorg-x11-Xvnc-6.8.2-100
kdenetwork3-vnc-3.4.2-11
archy@spirjr:~>

Computer P4/2.6GHz desktop.

Another computer, Celeron 2 GHz laptop, the same bug exists, no matter if locale is en_GB or en_US.UTF-8.