I tried to answer a question from a fellow user about problems setting the jenkins base url on the config page (or rather how not to set it)
and tried to set it to /jenkins/ without protocol and hostname.

This leads to an error in the logfile like this:

13.03.2012 00:33:27 org.jenkinsci.main.modules.sshd.PortAdvertiser getEndpoint
WARNUNG: Failed to advertise SSH port
java.net.MalformedURLException: no protocol: /jenkins/

this repeats occasionally (either when reloading the config page or maybe just every few minutes I'm not sure) and after some time, I get an out of memory error:

13.03.2012 00:33:27 hudson.triggers.SafeTimerTask run
SCHWERWIEGEND: Timer task hudson.slaves.NodeProvisioner$NodeProvisionerInvoker@1431174 failed
java.lang.OutOfMemoryError: Java heap space