Comment 175 for bug 147464

Have being using Transmission (1.75 to 1.91) for over a year in Ubuntu 9.04 to 9.10 on my Toshiba Satellite L40 laptop connected to the Internet via built-in Atheros AR5007EG wireless card installed in mini-PCI. While using Transmission I discovered that downloading from large swarms at high speed resulted in regular system crash (kernel panic) within 30 min to 1 hour. Recently it turned out the issue is system-wide, i.e. any heavy network activity triggers system crash. My search through Linux support community made me think that a bug in Linux kernel which causes i/o stalls in some cases (seems has been fixed in kernel 2.6.32) could be responsible for it.

Recently however I have found a hardware problem in my laptop. The PCI chip (not the CPU!) lacks proper cooling due to limitations in laptop design, mechanical defect in its radiator and partial blocking of ventilation slits by dust. After fixing mechanical problems my system has become rock stable. Still I was able to trigger system crash by heavy i/o activity - while downloading at ~2.5 MBits/s over wireless and transferring lots of data (~10MByte/s) via IEEE1394 PCMCIA card simultaneously and for a prolonged time providing that a temperature of cooling air is above 24 deg C.

Problem solved.
Conclusion: before reporting a software problem, it should be wise to check all your hardware carefully...