Thanks for your reply.
Just in case I did not explain properly when I said I figured it out - I figured out the cause, not the solution.
I would like to work with you to fix this, so I would like to make the following points in response to your comments above:
> There are no known menu issues on neither of the Theme
Well I have an menu issue, so you have one now :-)
> Even when you decrease the font size in browser....
I am not sure what you mean exactly by this but to be specific:
If I do not set a MINIMUM font size in FF and then increase or decrease the font size in the browser, the text remains vertically centered
Only if I set a minimum font size in FF then the font sinks to the bottom of the menu bar
> My guess is that this is an outdated FF browser
No, I am using FF 10.02
> or there're some installed extension that are causing the issues.
No, because as I indicated, your themes are the only ones that this is happening on.
I have been developing my own themes for Drupal and WP for 3 years, have worked with many menus on many themes and this only happens on yours - this would indicate it is not extensions....
> Here's FF at the minimum font for both Themes:
Not sure what you mean by this
Either minimum font is enabled or not, and then set at a particular size.
Based on the above I would say this is an issue that should be looked at...