Not a stooopid question at all
And one gets asked quite a lot! Laptops tend to come with 5200RPM drives... and many people that complain of dropped frames are trying to capture to 5200RPM drives
Now whether this is because older/lower spec drives tend to have 5200 drives or it's just the drive itself that's causing the problems is something I'm not sure of!
When I get the time (and a new 4-pin to 4-pin firwewire cable!) I'll test and post the results