Norton Utilities issues

Hi, I'm hoping someone can help me with some issues I am having.

I recently renewed my Norton Security subscription and took the opportunity to install Norton Utilities. The first thing I noticed after it had run for the first time was that I lost my access to Twitter, and also all the recent file lists from Word, Excel etc. This makes it inconvenient to use Word and Excel, and also means I get warning messages about suspicious activity every time I have to manually login to Twitter again. More troublesome, however, is that while NU is doing a Registry check it crashes my browser (Firefox, latest version but I can't find the version number) without any warning. It must be deleting something that's needed for Firefox to run. Oddly, there is a strange hiss on the speakers when this happens, but I don't know if this has any relevance.

Other than uninstalling NU again and binning it, is there anything I can do to stop these problems from occurring?