NodeID appears as 0 with Internet explorer

I've been testing signup for 4.6 on my site and have found that it isn't working correctly for people using internet explorer (tested on ie6 and 7). FF (tested 2.0) works perfectly, but when people sign up for events using IE the system thinks that the node id of the event is 0 and enters 0 into the signup_log table for nid and the confirmation message doesn't list the correct %title variable (nothing is returned from the variable). Any assistance would be greatly appreciated.