It hasn't given me any error yet, but if I try to add let's say two additional pages, it replaces the last two previously on the menu. I haven't tried swapping themes yet, but after digging a little more online it looks like it could be a hosting issue. See this link and I've seen other similar ones:
http://wpquestions.com/question/show/id/4290
I'm on the phone now with the hosting company to see if this is a possiblity, but I'm really pretty inept with hosting issues. I may try swapping themes to check that out too though.