I have a problem with the jquery show function in firefox.
Situation: I have loaded a iframe with an aspx page in a popup (fancybox). In that aspx page I have a button
I had a similar problem and my solution was to do
$("#psharebutton").css("display", "inline-block");
instead of
$("#psharebutton").show();
A jquery "show" is identical to setting the display style attribute to "block". I found that I needed "inline-block" for firefox and chrome (I didn't need this for IE). I believe (but have not confirmed) that jquery is smart enough to know what the previous display value is and use that, but in my case I started out with display set to "none" so there was no previous value.