disc? floppy disc? cd disc? You can do this quite easily just by copying the map onto the floppy disc in windows explorer, or using cd-burning software to burn it onto cd.
what file(s) did you copy? just go into ...\Warcraft III\Maps\ folder and copy mapname.w3m or mapname.w3x
also, your burner may be screwed up, try burning again... I get wierd "errors" with Nero sometimes when I burn and it says it's successful, but the disc is actually empty.
take a screenshot of where you can see 'warcraft III' but not the maps themselves. hit the print screen button your keyboard, and then paste it into microsoft paint, save it as a jpeg, and then post it here.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.