I am a firefox user and I have had zero issues with RC1 until someone told me that my site was not working at all in IE8, so I loaded my site in IE 8 and sure enough...
Take a look at it in both browsers...
When I look at it in mine it seems to cut off and stop loading completly after the first course listing.
FYI - This is a straight install, no mods or editing of code in anyway... I have tried a couple of other themes thinking that it may be that but I get the same effect. Any ideas???