Did you ever solve this problem? I am getting the same issue on JBoss 3.2 on freebsd, using database connection pooling to oracle, as described here: http://tinyurl.com/78w2w
The tomcat server in jboss is used to support our business systems. Everything will be going fine for maybe a day or two at a time, then due to cause-unknown, everyone will start getting this error, and obviously no database connectivity. (At that point the first person to notice emails me and I have to shutdown/restart JBoss). Initially I thought this was due to stale DB connections not getting closed (that DOES happen sometimes, but the cause there is known - poor coding), but often that appears to not be the case, like this morning when it began to happen with only 22 connections open (my min/max pool size is 5/100).
I'm wondering if anyone else has had this or other problems with the connection pooling algorithm.
Thanks for any advice,