FCP X Freezing Issue

Finally got my new iMac, FCPX, converted or retrieved all my old unedited video and started some new Events and Projects to work on. Everything has been working fine - performing basic cuts, transitions, exported video - all good. Today I tried to add one of the built in titles to one of my projects on the go. As soon as I pulled it over to the front of my timeline, the computer started chugging and within a couple of seconds it froze. I couldn't exit out of the program, move the mouse or anything. Had to do a hard re-boot to get the machine running again. When I re-opned FCPX again with the same project/timeline, within a couple of seconds it froze again. Another hard re-boot. This time when I opened it, I took the few available seconds to quickly select the inserted title and delete it. As soon as I did that, everything was fine. It seems every time I try to insert a title, it freezes. Does anyone have any idea why and what I can do about it (other than stop using titles)? Thanks.

Late 2012 model iMac, i7, 16gb, 1tb fusion, 2gb video card.

Not sure of the version (can't check right now - at work). I'm assuming its the newest version. I just downloaded and installed it from the Mac App store 2 weeks ago. I immediatetly did an system update as well. Events and projects are being stored on the 1TB fusion drive. Not sure how to answer your rendering question. From what I see, there are no background tasks occurring within FCP. The video imported was imported as both proxy and optimized and this happens whether I use the proxy or optimized files. I have seen some postings on other sites indicating the problem occurs with the main user account and that the solution is to create a new account and edit from there - apparantly it will work fine with the other account. I'd rather just use the one main account if possible.