1) the only time we’ve seen it that bad was due to corrupt font files.
The rest does sound like you have some sort of video driver problem.
Have you updated the video card driver?
I updated the video driver just after I upgraded to CS4, and I have checked today that it is still the latest.
The really weird thing is that the problems are not constant. Most of the time they are there, the rest of the time it’s OK. When there is a problem, it’s not all of them either.
I have now noticed that my pen works just after I open PS. However, if I change to drawing with the mouse, or change to another tool, then I just get the faint straight lines as in 2 above. I have contacted the maker to see if they can fix the driver.
I noticed that when I ran slide show the temp on the video card went very high, so I have ramped up the fan in case the temp is causing the card to throttle on me. Would this be likely?
However, I still don’t understand why I am getting the message that the GPU enhancements are being cut when GPU is not enabled anyway.
The error message is probably because when Photoshop asks the video driver for it’s name and capabilities, the driver returns an error. Photoshop is trying to find out if it can enable GPU support, and the driver is too buggy to even answer correctly.
I think you are right about the driver. I have now noticed that there is banding in even the simplest of gradients. In fact there is banding in the blue Photoshop splash screen – I assume that is not normal?
I have uninstalled and reinstalled the driver, and the banding is gone. Just all the other problems now 🙂