Server response time - affect on Google

How long a response before Google gives up

[brmmbrmm]

I'm pulling my hair out at the moment trying to solve a 25+ seconds response time from our server. The problem has lasted for at least 2 weeks. Anyone with similar experience? Will Google give up and demote us?
Also, I'm guessing the DMOZ editor who got submissions during this period will get bored waiting.

[ExpLarry]

I've got a site which has been up and down like a yo-yo (flaky hardware, too many hits ;-) and has had both complete outages and lousy response times on several occasions over the last few months. However I have never had the impression this discourages the googlebot (a very patient creature). OPMMV (other people's mileage may vary).