Following are compatibility complaints registered with Mozilla, re Firefox 7 (7.0.1) and Thunderbird 7 (7.0.1), running on iMac (Model MC309LL/A) with OS X Lion (updated to 10.7.1).

Firefox 7 will NOT:

- Access QuickTime plug-in (QuickTimePlugin.plugin), even though it is located in the system's Internet Plugins Library; attempts to add from the file fail because Firefox cannot 'see' the plugins in that Library folder (although it has access to several others, such as ShockWave).

- Even though updated to 7.0.1, the default theme has not been applied to Firefox's Appearance (and there is no way to manually accomplish such, as far as I have been able determine, even after examining Mozilla's help topics on the subject).

Thunderbird 7 will NOT open .eml documents. Apparently this bug has been known for some time and there is fix for same, but there has been no official update which takes such into account and made available to users.