Hi,
That possible, but as far as I know, every Cisco ASA (5505, 5510, 5520, 5540, and 5550,
information from http://www.cisco.com) uses the save image (asa842-k8.bin). So, I would suggest that the file might have been corrupted :(.
The most important is that you managed to have it working properly :)
An important point for those looking at this post, the "no interface" problem may also come from using the repack.v4.1.sh script to repack the asa file. The v4.1 script is only for VMWare. For Qemu and VirtualBox, you must use the v4 script, otherwise you have a problem of interfaces and slot0: during startup. But it's only one of the multiple problems which my occurs :s
B.R.
PS : if you're using the GNS3 1 beta 3 and managed to save the configuration, could you share your configuration in that post please :
http://forum.gns3.net/topic12182-10.html