Adding Fonts To My Mac???

OK I'll try and make this short. In june I bought a macbook pro to start my "switch" from PCs. I loved my MBP so much that I decided force myself to completely switch and I bought a iMac for home. But at work I still use a PC (graphic design) and im nearing the decision to kill that PC as well and buy a Big Mac Pro, so today I took some of the fonts that I use on my PC and put them on my iMac and MBP. Everything seems to work, except my Gmail and some of my hypertext links in Firefox are one of my seldom (alien type) used fonts and its annoying. So when I look at Gmail its like in a very hard to read font. I looked in all the settings for Gmail and firefox and i cant figure why its going to that font? Viewing this forum and all other pages is fine, just Gmail and some hypertext links are screwed up, any ideas? Also its doing it on both macs not just one. Thanks!

Try using Linotype Font Explorer. It's a free download and you can activate/deactivate fonts with ease. You can also clear font caches, which could help your problem. Try deactivating all fonts except system fonts first and see if that helps. It's also useful to check that Arial and Verdana are activated as many websites use them.

Where do I go clear font caches???? For a temp fix I just removed the font from the fonts library and it worked, now its back to the correct font. But I still wonder why it goes to that font style? Seems odd to me.