There was a post like this, but it was very old, here
I have a similar problem, although I don't think it's at exact time increments. But I could very well believe it has something to do with ACPI or APM (knowing nothing about those things except for the fact that neither have ever worked very well with regard to suspending and waking my machine).
I may follow the bios settings suggestions from that post, but I'd like to not make changes that I don't understand. I also see earlier in that thread a suggestion to modprobe. Which of these options seems better, and does anyone have a clear description as to why this kind of thing, generally, happens? Right now I'm just setting everything to autosave pretty frequently, which is very annoying. I may have to get a wired keyboard if I can't solve it.