there is a saveas method as well, and i am not certain if it has the same limitation. i have had some problems with those methods as well, and did bypass it with flFile so i am not the best person to ask
check out the extending flash mailing list on flashguru.co.uk there might be an answer floating in there somewhere. (use google to search the archives)
also guy watson (flashguru) and burak (asvguy) did a mxp to give filesystem access pre 7.2 but it only works on windows machines (nt,2000,xp), but u can force a install of that mxp.