Mozilla Suite 1.7.12, PM 0.9.1
Needlesearch 3.0, specifically the
Modern Theme icons version
Needlesearch adds a search engine toolbar to your browser.
Search history is cleared by a context menu option on the Needleseach Toolbar.
After installing PM 0.9.1, search history that I clear from the Needlesearch Toolbar reappear upon restarting Mozilla.
I have the same results with a clean profile and installing PM before or after Needlesearch.
Did not have any problems with 0.8.7; not sure if this occurred with 0.9 as well