Hello
First of all, sorry for my English, I am French (thanks Google Translate!).
Dgrace, I think I encounter the same problem as you.
I bought the recoil kit Aimtrak as well as the same power supply that was advised on the manual to upgrader my gun bought from the same shop in 2011 (my firmware is 9.17)
At home also, the recoil does not work correctly: when I plug it and I shoot for the first time it works

against the second attempt nothing happens ...
If I wait a few minutes and I start again, the first shot works but the following not.
I think the problem could come from the power supply, may be a problem with the amperage (3A may be not enough) because it looks like the power "tires" after the first shot and that " It needs to be recharged to re-run.
I sent an email to Andy of Ultimark in case he's already encountered this worry.
I'll let you know if I'm making any progress
