It sounds like a memory issue.
I was a bit baffled by my issue as I didn't think that downloading torrents with transmission would be related to a memory problem. I opened Activity Monitor/System Memory tab and started up my torrents. I watch the memory usage and noticed that It would slowly start filling available memory. The system would consistently freeze when I passed 3.6GB. I then opened a large document in Photoshop and did some heavy work with it and was able to replicate the freeze.
Test to see if this is the problem.
Use the boot-flag
on startup. This will limit the memory that OSX uses to 2GB. Run your torrents as usual and see if you still get the freezes.
-The fix
Slashack over on insanely mac posted some modified 64bit kexts which fixed the problem for me. We are not using the same chipset so you will have to see if one of his works for you.
http://forum.insanelymac.com/index.php?showtopic=127611
-Using maxmem as a fix
Try the maxmem flag on boot and if it works add it to
com.apple.Boot.plist (located in
/Library/Preferences/SystemConfiguration/) The syntax goes something like this:
Code:
<key>Kernel Flags</key>
<string>maxmem=****</string>
Replacing **** with the amount of memory to use. Many people have reported 3456 (3.38gb) works well. I have pushed mine to 3584 (3.5gb) and have not been able to make it freeze.
Network related freezes
Most of the time people with your symptoms have the problem with memory. I have heard others who have had issues with their lan drivers. Id use maxmem to test for the above first.