Yeh, are you sure you've opened a map?
At the left hand side their should be three folders.
Expand the top one and their will be another 40 odd folders. Expand one of them and select a map. (3.0 Edits Pallet Town in FireRed)
Hope I helped ~
hey i gotta question, maybe u'll know, maybe not... i have AdvanceMap downloaded and the file unzipped, and the same with the ruby ROM i found online, but when i open advancemap, no map shows up for me to edit. can u help?