I'm getting somewhat similar errors (i.e. the "os_schedule.. " part), and the only drivers that work stably (no errors) are from the 195-series. Ever since, there's been problems. X tends to hang for long periods of time here when the errors occur, though it rarely crashes. Hardware is not the same, I'm on a Dell laptop with an NVS 3100M. I can most easily trigger the problem with console switching. Here's the thread in which I reported the problem:
I keep that thread updated with testing from the latest releases, to determine if the problem is solved or not. Never gotten any official response though. Hardware fault is not likely, since everything is very stable with the older drivers, and Windows 7 works fine.