I found a way to get the opacity to work with Mozilla type browsers, hope you would implament this in your CSS for use users with Mozilla and use the x79 style.
/*cat title alpha*/
table.alphame {filter:alpha(opacity=75);-moz-opacity: 0.75;}
span.alphame table.tborder {filter:alpha(opacity:75);}
/*alpha trickery--since the preceeding 'body' makes these more specific, they override the standard attributes, even if they get defined after these*/
body td.fdblues {background:transparent;}
body td.fdflcc {filter:alpha(opacity:50,style=3,finishopacity=100);-moz-opacity: 0.50;}
body td.fdthtext,body td.fdthpic {filter:alpha(opacity=75);-moz-opacity: 0.75;}
body td.pbc {background:transparent;}
body td.pbcbe {filter:alpha(opacity:75);-moz-opacity: 0.75;}
/*make sure that any possible second levels stay at full (relative) opacity*/
.tborder .tborder,.alphame .tborder {filter:alpha(opacity=100);}
.headernav .vbmenu_control {filter:glow(color=#001020,strength=2);}
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