EndNote X1 and Word 2007 problem

I haven’t used Endnote for a while and since yesterday when I was trying to format all citations in a text I have been writing, Word program would freeze up and I had to end it with Task Manager. Reinstall EndNote didn’t help and Office Diagnostic can’t identify any problem.

Could this be associated XP SP3? Since I haven’t used EndNote to format citations after the OS update. Yesterday was the first time.

 Thank you guys!