odd behaviour with overly long lines in irssi

Binary package hint: screen

Description:
Overly long lines not to wrap correctly and making the content of the irssi window previously visited to "leak" where the wrapped line should continue to. This leaked text can be copypasted, but it wanishes if the screen is redrawn with ctrl-l.

server running irssi in screen:
xen virtualized Ubuntu, upgraded from Dapper LTS to Hardy LTS,

Linux myrtti.fi 2.6.19-4-server #2 SMP Sat Oct 6 01:59:49 UTC 2007 i686 GNU/Linux
Description: Ubuntu 8.04
screen 4.0.3-7ubuntu1
irssi 0.8.12-3ubuntu3

client computer running ssh-client connecting to the server:
Description: Ubuntu 8.04
Using xubuntu, enabled fglrx, hardy-proposed

happens with vte's like:
* Terminator 0.9 bzr 306
* xfce4-terminal 0.2.8-4ubuntu1
* tilda 0.09.4+cvs20071012-1
* eterm 0.9.4.0debian1-2ubuntu3

DOESN'T HAPPEN if:
server running irssi/screen is
Linux kengu 2.6.24-12-generic #1 SMP Wed Mar 12 23:01:54 UTC 2008 i686 GNU/Linux
screen 4.0.3-7ubuntu1
irssi 0.8.12-3ubuntu3

Expected:
URL's and long lines wrap up nicely, url's are clickable, no information leaks from previous windows to the current one.

Happens instead:
see attachment files

[10:43] <+Myrtti> it really freaks me out to see "confidential" text mixed up in a casual conversation
[10:43] <+Myrtti> like "so which venereal disease did you get from that idiot" on #ubuntu-offtopic