why can i only export as flash 5?

hi. i'm making a flash movie and i want to have it in a video format as well as swf. i've been trying to export it to mov but it tells me i need to export it as flash 5 or earlier. i tried this and it seemed to work but i'm afraid i'll have actionscript problems because if i'm not mistaken flash 5 was actionscript 1 and i'mm using flash mx which is actionscript 2. are there variables that i'm missing here? can i work in flash mx and not have to worry about script problems or is there something simple that i'm doing wrong that makes it so i can only export to fflash 5 or earlier? any comments would be helpful.

thanks
jeremy boyd