CS5 and Wacom woes

Ok internets I need your help. Serious issues are afoot. Going to write this as simply as I can, hopefully without swearing.

Photoshop CS5 is not recognising pen sensitivity UNLESS I do the following.

1. Uninstall the drivers
2. Restart pc
3. unplug wacom
4. reinstall driver
5. plug wacom back in
6. start photoshop

now this would be fine and dandy only that IF for whatever reason I need to/accidentally close photoshop or it crashes but as soon as I open photoshop again, no sensitivity which is a little bit annoying since I own a Wacom Intuos4 XL and I use pressure ALL THE TIME!

I have also tried the following:

1. a full format
2. reinstalling photoshop cs5
3. installing photoshop cs4 (same grief)
4. older drivers
5. starting/stopping services
6. swearing at it
7. unplugging wacom
8. different usb ports
9. updating motherboard chipset

Which is more troublesome is A has the same version of Windows 7 (ie 64bit) on his laptop, with photoshop, with the same drivers. NO PROBLEMS.

Which leads me to think is it my pc hardware? Is it the motherboard?

This is driving me insane, I need to paint. How can it be so tempremental? Just... why? I can't spend my life rebooting my pc every time I want to open photoshop.

I live with a software engineer and A who has been building pcs since he was in nappies and they don't have a clue.

Please... someone... help?