A friend recently purchased a Compaq notebook with a Core 2 Duo CPU and an Intel GPU. She noticed a significant amount of cursor lag. She returned it and got a Toshiba, also with Intel CPU and graphics, and is having the same problem. I don't know whether it's the same GPU; I think this one is the ubiquitous X3100.
I'm wondering whether the Intel graphics chip is causing this. I'm aware that Intel makes the worst GPU's, but she isn't doing anything strenuous - no gaming or complex graphics, just web and word processing. Has anyone heard of or experienced this?