invisible text in ssh and/or NX

I’d highly appreciate some help and insight into this issue:

After recent updates on some 12.3/13.1 machines (maybe covering half a year) a couple of strange
and annoying things popped up.

The most harmless is the degradation of scroll bars to useless screen elements (too narrow to use, missing arrows, buggy drag speed, funny jumps, unusual and inconsistent click behaviour) which I could somehow solve by deinstalling everything related to “adwaita”. With exception of evince which continues with unusual scrolling (GoTo instead of page scroll) I consider this solved. I think this scrollbar thing may be somehow related to the more severe issues which are still unsolved. I guess this could be some major GTK rework (hiding/removing menus from FF and evince is also part of that?), but I’m clueless.

a) re-connecting to a machine via NX suddenly causes several programs to display invisible text. While I could reduce this by disabling a couple of NX features (everything that makes it fast), some programs still suffer - but only after a reconnect. The full problem was such that not even a konsole would display anything. However, starting a new konsole or application would work fine. Rescaling/reset-ting an old konsole doesn’t help. Neither menus nor shell content would display anything. Other programs such as xemacs are not affected at all. The NoMachine NX client (latest 3.5) is on a 13.1 machine, also with adwaita removed.

After disabling some NX features (disable backingstore and composite) the konsole works normally after reconnect. Some other programs still suffer. I just found that also LibreOffice will turn white. Only icons will draw correctly in these programs, all text in menus and documents is drawn in background color.

b) While trying to figure out some details I tried to start these programs in a regular ssh connection. This also results in completely white text in menu and content! This ssh connection is from a Suse10.0 system to a 12.3 machine, thus the issue is obviously on the 12.3 side.

Searching around I found some hints to downgrade libCairo…but…I have other 12.3 machines which didn’t yet get the last updates…and these machines do not show these problems. Both report the same version of libCairo, though.

We’re using KDE3.5 on all machines (I don’t want to waste my time for/with screen cosmetics)

The main questions:
a) what is responsible for this bunch of problems and how to stop it?
I’m thinking to use LD_LIBRARY_PATH to point almost everything to copies from an un-updated machine and then remove libs step by step. But this would only work if the troublesome stuff is loaded with the application I’m testing and not already running on the machine.

b) I wonder how to revert the updated machines back to working condition, facing that the last update changed 1000+ packets. Is there a way to downgrade the system to a particular date? E.g. where would I find updates which are about half a year old so that I don’t have to jump back to the version in the 12.3 ISO?

c) How to update the other systems without running into the same trouble? I need to isolate the problematic stuff and only prevent thet to be updated.

thanks
GG