Forum OpenACS Q&A: Response to Ns_Pool: invalid block
Do you have enough stack space allocated per thread?
Are you in a position where you can set up things without Jerry's patches? This would help isolate things. I ask because my AOLserver 3.3ad13+PG 7.1.2 site stays up literally for months at a time. I just added a 1/2 gig of RAM to it last week - uptime was 200 days. I'd restarted AOLserver a few times in the interim as I did site upgrades but other than that it's up all the time and I've never seen this problem you describe.