Hm....
I just made an SRM with snes9X v 1.51 and it worked fine with zsnes. Are you 100% sure you are sending the right file.
Can you try:
1) make a brand new folder with nothing in it
2) load your rom in Snes 9X,
3) go to options => Settings
4) Left of directory switch the drop down to "SRam" (Default is ./Saves)
5) Browse to your new directory
6) File => Save Other => "Save S-Ram Date"
7) Confirm the file is in your new directory.
Change the extension to ".jpg" and attach it.
--JP