True, that used to be a big problem for me as well until about 1 year back. I think it was Karmic that finally solved it on all my laptops.
Suspend works perfectly for me on a Dell Studio XPS, an EeePC, and a MacBook.
What kind of notebook computer have you been using?
On this Dell Mini 10, X will eventually crash following a resume from hibernate, then I drop to low-graphics mode and avoid doing an actual reboot for as long as possible, just hibernating my low-graphics state.