I too am having problems with shutdowns, freezes, and RAM deterioration in Windows XP. I don't freeze or go low for days until I get 1-2 Torrents downloading and then my RAM is gone in a little less than 45 min.
My current configuration is:
ASUS P4C800-E Deluxe MB
P4 3.4 Extreme HT 800 Mhz Processor
Corsair Xtreme PC-3200 RAM - 1 GB
Physical Memory Prior to starting BT:
Total 1047276
Available 798184
System Cache 498848
Physical Memory after 35 minutes:
(Running only two open BT DL's of 435 MB and one is 3.5 GB)
Total 1047276
Available 58659
System Cache 965189
I am posting this message now before I actually freeze
I usually freeze after about 45 min of use and doing other standard things on my PC like browsing the internet. I have no spyware, no malware, and the only processes running are windows ones, my firewall and antivirus, a printer monitor, and adobe plugins.
I also do not freeze or run low on memory EVER unless I am running BitTornado 0.3.7. I can run for days or weeks without a reboot and tax my system resources heavily while working and not freeze.
Hope this helps. If there is anything else I can do to help provide more information just ask. I will provide you with anything I can.