Slow script problem Rated 5 out of 5 stars

I have been using this extension for years but lately I am having problem when opening new tabs:
A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete."

I have stopped using the Tree Style Tab but I am lost. Please look into the problem.

This review is for a previous version of the add-on (0.10.2010051201).