Could my iMovie software be corrupt?

Hello everybody!! I'm a new Mac user, but my BIL worked at Apple and I would consider him an expert (lucky for me!). I successfully created a short movie with a song attached in iMovie and also turned it into a Quicktime movie (go me!). It was pretty easy.

However, now every time I try to create a movie and save it, it tells me the file is rendering. I read up on rendering, but the problem is that it NEVER stops rendering. I even tested this with just one clip and no music. It shouldn't take forever to render. It also won't let me save the file - again because it's rendering.

It's also IMPOSSIBLE to drag a clip with your mouse and shorten it's length. I have tried everything (including reading all the tutorials) and it just doesn't work. BIL looked at it quickly this a.m. before work and he said that he has always had issues with dragging and shortening a clip and showed me a shortcut, but that didn't satisfy me. LOL! I want to DRAG it with the mouse (easier and quicker).

If anybody has any suggestions about this rendering thing, that would be great. BIL suggested re-loading iMovie on my Mac (OS X Tiger 10.4.10), but I'm nervous to start removing and adding software if I don't have to.

Thanks!