Great Search addon, but .. a litle Bug? Rated 5 out of 5 stars

This is a great add on. The default search in Thunderbird is too complicated. Too many buttons and clicks. Expression Search makes it as I would like the search to be. But something doesn't work very well. Once every 2 times when I click <CTRL-Enter> I go to the default thunderbird search. How can I avoid this??

edit:
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Once every 2 times, It does not create a virtual folder but it does the search as default in thunderbird (it opens a new tab with the search results and the possibility to filter the search (not for me, for me etc.., people etc)).
I hope I made myself clear.

This review is for a previous version of the add-on (0.8.4). 

please describe in more details, like: OS version, TB version, addon version, how to reproduce etc.
Do you see any error log in 'Tools'/'Error Console"?