Changed font in custom.css & dashboard, still not working

I have gone in and changed the font larger on the dashboard under design options and in the custom.css in the ftp. when you go back to my page it still shows it very small. When you hit the refresh button or go to a diff. page on my blog you can see that the font gets larger again and then immediately goes back to small again. Any ideas? Are there several layers of changes I need to make other than the 2 listed above? if so..what would they be and where do I change them at?
Thank you for your quick response,
Tracy R