Some Foundation is Crashing - Slows Interface

Question

Have noticed this several times over the past month.
Bootup, login and all seems normal. Until you start using the interface.
Example:
- Typing text in Safari is very slow. Press and hold a key and the characters stutter onto the screen.
- Scrolling in Safari was slow and jerky.
So I launched Console to look at system.log and noticed:
- Scrolling in Console was slow and jerky too.
- Usually when this happens the 'magnify' action of the dock is not very smooth either.
Didn't notice anything obvious in system.log (It would have to be obvious since I don't study OS X logs).
So, something low-level must be crashing. Graphics card driver? Core image or Core something or other?
From the profile you can see 2007 MP with dual, dual core processors (2.66ghz) and NVIDIA 8800GT (Legacy, which means the one designed for MPs with the PCIe 1.3).
Based on zero evidence, I suspect the 8800GT driver. Well actually I do have evidence. When I had the 1900XT installed this didn't happen. But I was using 10.5.2 then too.

Answer 1

Create a new account, name it "test" and see how your apps work in that User acct? (That will tell if your problem is systemwide or limited to your User acct.) This account is just for test, do nothing further with it.
Open System Preferences >> Accounts >> "+" make it an admin account.
If the problem is present in the test account also, then it is systemwide. In this case try repairing this with the 10.5.3 Combo Updater. This is a fuller install, as opposed to an incremental "delta" update so it should overwrite any files that are damaged or missing. It does not matter if you have applied it before.
Remember to Verify Disk before update and repair permissions after update from /Applications/Utilities/Disk Utility.
-mj