This issue should be solved.  The script now checks to see how long we've been mining a particular coin, and if we have more than a threshold (currently 10 minutes), it switches to the new coin immediately.

This should at least partially solve the 'flapping' issues we've been having where the port switches between two coins because of very minute changes in price.

I'm also working on a much more robust price determination algorithm that will use averages from multiple sites.  Of course, it doesn't help that vircurex, btc-e, and bter are all down right now.