For sometime now, and once in the distant past before I upgraded to XP
Pro, I had this problem.

I can input through the keyboard, but a now and then, often in fact,
the on screen display will not show my input characters, then after
about a 10 to 15 second delay, it will all 'paint' onto the display.

During the lull pointer click, though not pointer movement, is locked
out. All on screen activity is frozen, until that "cache" or whatever
it is dumps the input to the screen. Then we go on for another 15 to 20
minutes of input until it happens again.

On line, or offline, it is consistent. Word processor, or mail program,
or even Usenet using the google groups messaging form.

I expect it, in fact, any moment now.

Don