Comment 179 for bug 147464

I had experienced this problem (system becomes hardlocked during heavy network transfer) on Toshiba Satellite L4 laptop in Jaunty and Karmic. Later it turned out there was a hardware fault in one of on-board inverters. Just have my motherboard replaced and the issue disappeared completely! No more system hardlocks, neither error messages in system logs for several days.

Conclusion: while reporting software failure one has to be cautious about the conditions of hardware. It even worth it to ask a specialist when possible. These faults are not easily identifiable, and manifestation can be contr-intuitive.