If your system locks completely (i.e. can't change consoles) then
something is in a tight loop.
My guess is you're seeing a problem with dev->tbusy mis-use which I
fixed in 2.0.2 (approx). If you see a problem after this, I will need
some info, e.g. kernel version, driver version, machine configuration,
software, what you're doing at hang time etc.
All of my PCI machines are never up longer than a day or so as I
multiplex between different OS's, so I've never seen the problem you're describing.
Regards,
Dave