System font display issues since upgrading from Snow Leopard to Lion
First, you said you are on 10.7. Have you run the updaters to update your system to 10.7.3, with all of Apple's updates and patches?

Most likely you are dealing with duplicate fonts that are incompatible--old ones from your old system and newer versions of the fonts with the same names that came with 10.7.

Here are some things you can try:


Run the Font Book application, selected all the fonts, and run "Look for Enabled Duplicates" and disable the duplicates. Then select all fonts, run "Validate Fonts", and remove any that are reported as corrupt.







Use a utility like Cocktail to delete all your font caches, repair your disk permissions, and reboot. (There are several other programs that provide you with a way to delete your font caches, and there is also a method to do this via Terminal and the command line).





Download the free TinkerTool and see what it reports about your system font settings. See if you can use TinkerTool to reset the font settings to their system defaults.




If none of the above work, or if you learn from Font Book that the basic fonts that you need are corrupt, then you should re-install 10.7.3 on your existing system (this will not hurt your data) and run Software Update and apply all patches. But first you need to delete any duplicate fonts or corrupt fonts.

I believe you can download the Lion 10.7.3 installer from the Mac App Store onto your existing installation and run the re-installation procedure from there.