just install 9.5.196 and when houdini starts it draw a warning in console window:

Warning: OpenGL frme buffer object not available. Upgrade your driver to a minimum version of 87.76 or some Houdini display features will not work.

I test on my laptop (vista x64 nvidia 177.x, 175.x, 158.x, 169.x) and on pc (win2003 x32 nvidia 91.x) - everyone I got this warning. And some menu artifacts are occured.

nvidia 7600go, 6600gt

me too;

Warning: OpenGL frme buffer object not available. Upgrade your driver to a minimum version of 87.76 or some Houdini display features will not work.

windows XP pro 32bit

nvidia 177.x

houdini-9.5.197-win32-vc8

geforce 8800GTS 512mb

So anybody else have same problem with last builds? I think this bug start from 9.5.195.

added:
It was fixed in 9.5.198. Thanks.