For TGB_Dual:
First of all create a seperate sub directory called "trade". Then set that to your save directory by going to "Options" and then "Directory" from the TGB_dual menu. Now copy the pokemon crystal saves games into the trade directory. Change the extension of the one of the save files from "sav" to "sa2". Leave the other as "sav". OPen Tgb_dual again and load rom whose save file with the sav extension into GB1 and the the load the other rom into GB2. It should work with save files.