Hi su1man
Sorry I forgot to include a link about deleting the Preferences file. This is the page I usually link to in these cases, as I think this gives the best explanation:
Photoshop Tips: Trashing the Preferences File | CreativePro.com
Unfortunately, Photoshop does occasionally get screwed up for no apparent reason, but 9 times out of 10 this procedure will get things back to normal. Glad it worked for you.