Outside of ArchiCAD possible issues (likely or unlikely I have no clue) or the biggest probability (Your new Video drivers- go back to the previous version or a slightly older one to see if this fixes it)....
Outside of all that I'd say, hands down, that it's because you're using Vista.
Now I know that it's the latest (well only a few years old, wot? And still with problems of amazing kinds) Microsoft money-grabbing release, but from a tech perspective, it's about as good a quality product as the plastic stuff we get from Taiwan that is replacing all the hand-made, say, baby toys in the USA. Capice?
So regardless of WHAT application you're using, if you have problems on your computer, pretty much then can
1. Be solved with Windows XP within 15 minutes
2. Have no support or fixes or solutions in Windows Vista (any variant).
Partly the reason for this is, without going into a whole topic change, is that the big Microsoft bully decided to further monopolize (after it's anti-trust facade suit- did we expect anything less?) by charging insane amounts for developers (can you say in excess of 1mil USD?) to have access to develop drivers and code USING vista. I.E.- translated: they made a crappy product with horrible developers (total kids) who were cheap and new at programming and then decided to “fix” it by charging people about 300x the usual amount to get access to fix their mistakes, and then touting to businesses the tiny possible “benefits” of upgrading TO vista (there are none, not one, not even after 3 years of working on it- no reasons at all to have vista over XP)…So of course, being that no one likes being freakin’ bullied, half of the developers tried to protest by refusing to pay (and the rest simply couldn't afford it). Microsoft in effect created a lock and more monopolies for big business for whom dropping a few mil in development access fees was no big deal (kinda like Pepsi and Coke working together to kill any and all other competition). These morals and ethics and as we know, create lower and lower quality items (over volume and profits) for big businesses. So while we have drivers for/from, say the major vendors (Dell, Toshiba, Sony, etc) smaller non-billion-dollar-profit companies got totally wedged out (HP, Asus, DFI, all the smaller component manufacturers). This wouldn’t apply too much to VIDEO CARD DRIVERS except that Nvidia and ATI both protested originally to this bullying and were absolutely REFUSED access to the code TO develop drivers for their customers (what other video card manufacturers are there??? Get it?) and as such, because MS refused to work with the MUST HAVE people they made an operating system that simply refuses to work correctly with 3d apps and challenging GPU issues- there is no real way to fix Vista problems, as they are IMBEDDED IN THE OPRATING SYSTEM ITSELF..
Nvidia and ATI finally had to fork out to get on the wagon, but they had problems as Vista sucks, plain and simple. They can NOT fix MS’s crap and mistakes. So drivers are buggy, problematic and have no fixes or solutions. PERIOD. This is most noticeable in the 3D field- games, architecture, modeling, movies, and multi-media-3D: things simply do not work. - The field where we most NEED to have things stable!!!!
To FIX Microsoft’s messed up Vista OS isn't worth the work, let alone to have to PAY to be allowed to do it, (pay to fix someone else’s crud and horrible work??? WTF how does THAT work or make sense??? Can you see why no one wants to deal with such strong-arm blackmail and bullying tactics??? Its MS’s fault and problem, they have to do better work- but wait- NO THEY DON’T AS LONG AS PEOPLE BUY IT!!! *rolleyes*)
….So even though the price to get in has dropped, the people who COULD do it, simply know it is a waste of their life energy and are working on things that make more sense of their time and efforts.
IF that doesn't help convince someone to go back to windows XP then the side effect is simply=
You’re problems will continue in 3D work on Vista.
Years from now we'll all know vista as the big wool-over-the-eyes trick that Microsoft did to make money. It is about as low a quality product as one can create without breaking any laws.... Wait! There ARE no laws about this!!!!!!
Ah HA!
So it's as low a product as one can release on the unknowledgeable world of end users without getting every single copy shipped back within 4 weeks.
Pull out those windows XP cd's and reinstall.
And hopefully ArchiCAD will NOT try and make fixes for Vista. Simply put, it won't help in the end.
Open GL and 3D issues are absolutely profuse in vista- completely and absolutely constant and non-ending. Looking at the architecture of how they created the OS logic, the only fix is to start with a different OS if you do 3D work.