Our EZW 7 just started locking up every time we try to edit songs or add a new song. We don't seem to have the same problem in the presentation or media sections. 

Any ideas what would be causing this and how to fix it?

I am having the same or a similar issue. Every time I try to change the theme, everything locks up. I have restarted EW, I have restarted the computer, I have uninstalled and reinstalled EW and it is still locking up each time I try to change a theme.

Not sure if this has anything to do with it, but it was recently decided that no illustrations could be used on the song or scripture slides. I have been trying to reset everything to a blank slide, but still have themes available for other slides (sermons, welcome page, special music, announcements, etc)

Jill, I would try creating a new profile using Profile Manager (you do NOT need to delete your existing profile to do this) and see if that locks up as well. If not, import your media from the old profile to the new one (a few at a time) and see how that works out.