Moving this discussion to the Photoshop General Discussion forum. Creative Suite 5.5 and 6 have been tested with Windows 8. Photoshop CS5.1 was released as part of Creative Suite 5.5 so it should work properly.
Perhaps if you can provide a bit more details regarding the glitches you are seeing the users in the Photoshop General Discussion forum may be able to provide some assistance.
There are no more updates for CS5 as CS6 is the current release. The main problem is the GPU drivers. See if the manufacturer's website has new ones. The Microsoft site drivers are usually out of date. If that does not work, then set the GPU mode to "Basic" in Photoshop's preferences.
[ eggnog typos fixed by admin ]
For now set your advanced GPU mode to Basic and see if that helps.
Edit: Oops, I missed that Curt had already said that. What Curt said.
Others have commented on the update aspect, but when you state:
some annoying glitches have popped up.
Can you provide details, on exactly what you are encountering? The more detail, the better.