Before you quit LW, control-alt-del & bring up task manager & see if there's more than one instance of LW listed as running. If there is, then that might be the reason. If it is, then search your computer using your comp search engine for LW & see if there's more than one copy. It's still possible to have 2 instances running even if you only have one copy by clicking on the shortcut too many times.

Just to double-check there's no viruses or anything, go to NorbiesWorld (click on link) & register there & use the Hijack This ... & post a report for him to deciphor. That'll give you the all clear or whatever ...