Weird Apache Behavior

Hello,

I have a webpage load balanced between three servers. One of these
servers randomly begins to collapse. The apache log file shows these
entries:

87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22813.jpeg HTTP/1.0" 200 12957 "-" "-"
87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22813.jpeg HTTP/1.0" 200 12957 "-" "-"
87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22815.jpeg HTTP/1.0" 200 21674 "-" "-"
87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22815.jpeg HTTP/1.0" 200 21674 "-" "-"
87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22665.jpeg HTTP/1.0" 200 20591 "-" "-"
87.98.225.39 - - [24/Aug/2007:11:47:27 +0200] "GET /foto/
thumb_22665.jpeg HTTP/1.0" 200 20591 "-" "-"

The 87.98.225.39 is the VIP of that server. The top command shows
there are constanlt 590+ tasks. 256 of them being httpd threads.

Anyone has any idea on what the problem might be?

Thanks,

Antoni