[jQuery] selectChain Plugin - Fires on Page Load

[jQuery] selectChain Plugin - Fires on Page Load

Hello,
I am using Remy's most excellent selectChain plugin (<a href="http://remysharp.com/2007/09/18/auto-populate-multiple-select-boxes/">http://remysharp.com/2007/09/18/auto-populate-multiple-select-boxes/</a>), but I do not want it to fire on page load, unless the top level select box has a pre-selected value.  I've tried a couple of ways to create that functionality, but I can't quite seem to get it right.  Any thoughts or suggestions to steer me down the correct path would be much appreciated.  :-)
Thanks,
Matt