Corrupt Alt-text / Display Driver Issue?

Hi all...my first post and a complete head scratcher...

I have an HP Compaq 8510p Laptop (T7700 2.4Ghz Dual Core, 4MB Ram, with dedicated HD2600 graphic cards. running Windows 7 Pro x64)


When I hover over any of my menu bar icons (e.g. Internet Explorer) the text buble (or Alt-text as it actually is I think) says what I am hovering over in a cream popup.
However, when I hover over the Windows "Logo/Start" icon, the Alt-text is corrupt, so much that you cannot read it at all. All other hovers are perfect as expected i.e. over the system icons etc.

I have also noticed it in MS Office in all applications (I have Office 2007 Pro installed) and in every ribbon, all icon hovers work as they should except when I open the list of font sizes from the drop-down list of values. All Font sizes are displayed in a corrupted/broken fashion, again I cannot read them.

Although I suspect it may be something to do with my ATI graphics driver, I do have the latest version installed.

As said it seems to be localised to those areas and does not seem to be getting worse or better. Totally annoying.
I have used other applications and all seems perfect, including Acrobat, COD Black Ops, Minecraft and Chrome etc.

Therefore I'm completely baffled. Any ideas/suggestions or previous experiences?

Thanks in advance.
Tink

Thanks both,
I have reverted to the HP stock oem driver and it has solved this issue, however I cannot now play minecraft. It says my drivers aren't up to date.
My driver version is now 8.6.3.2.

I have just installed the first win7 signed driver, 9.1, and it corrupts again...
The only choose I can think of is using an old Vista driver...if they are compatible? and working my way back in time until all is working.

Yep it was xp originally although there is a build approved for Win7. It was this approved HP driver set from HP that works for windows 7 but not minecraft for example.

Just thought it very wierd that the any.later drivers corrupt the display in only certain places and only in Microsoft software...

In effect it says to me that win7 alt text is not coded uniformly, else why would it only corrupt in the same places all the time? Naive maybe but what else can it be?

Displaying the word "Start" and the office font sizes is not graphically difficult necessarily..
I'll upload a few shots later when back on my desktop..