Is your web application or mysql instance crashing?
You might try adding autoReconnect=true
to your JDBC URL. Hat tip to Stephen Chambers, who seemed to offer the solution on the Struts User List today.
If you're a CVS/Windows user, and you're not using Tortoise CVS, you might want to look into it. It integrates nicely with Explorer and has recently had a 1.0 release. Thanks Francis Irving! Once you've installed it, try Timo's icons. They're my favorite out of the choices listed.