I had the exact problem you did (page numbers were way off to the right, etc.), and I was able to fix it by going into the Table of Contents menu. In 2007, click References > Table of Contents > Insert Table of Contents > Modify.

You then choose the level of heading you want to modify (in my case, it was Heading 2, so I chose TOC 2), and then click Modify. Click the Format drop-down menu, then click Tabs. I was resizing the TOC for an A5-sized document, and my tab stop ended up needing to be between 3.5 and 4.0. Play with it to figure out what you need by typing it in, choosing your Alignment and Leader, and clicking Set. You will then need to select the old tab stop and click Clear.

Hope this helps.

CCR