Font size changed?

I've noticed the last couple of days that the font size has got smaller. As a page loads everything is normal, then all the type including usernames get smaller once the page has finished loading?? All other sites are as normal, it seems to be just here. I've checked on 3 computers and they all do the same thing.

I've checked the user CP and can't find any font setting that my have been changed. Seems to be doing it with both firefox and IE.

This happened a while back as well, then it was normal and now it's back. Not sure why.

It seems to back to normal now which is good!