I have a 2g with 3.1.3 installed I used pwnage to create a 3.1.3 custom restore file.
Everytime I plug in my iPhone and try to shift | restore iTunes put the device into recovery mode and it stays that way until I pull the cable and restore.

What am I doing wrong?
Oh the only way for me to get out of recovery I have to plug the device back in and restore via a normal restore with iTunes.
Ive tried this on my mac and windows with the dame outcome. (I copied the 3.1.3 custom file over to my PC)