Snow Leopard plus FontExplorer X equals screwed-up fonts in Firefox (especially Helvetica).
- Google Search on “Snow Leopard Firefox FontExplorer X” reveals numerous incidents of CSS displaying incorrectly in Firefox (wrong font weight, wrong font style) when Font Explorer X is on Snow Leopard Macs.
- My Flickr thread contains a screenshot demonstrating the problem plus a useful discussion of causes and possible workarounds.
- Disabling FontExplorer X solves the problem.
Update: Buying FontExplorer X Pro and clearing font caches also solves the problem. (The problem is with Apple’s fonts, not with Firefox or FontExplorer X, but it takes mediation to fix it.)