I'm having this same issue trying to JB two iPod touches on my MBP. Problem is they've been formatted for windows but it says the JB was successful after a couple of prompts from iTunes saying i must restore iPod to in order to connect. But on reboot, there is no Limera1n icon.
I asked this question on here before, regarding whether It will cause any conflict with the JB process if I use an iDevice formatted for Windows on a Mac and someone on here reassured me it wouldn't.
However with my testing so far, I think they were wrong because I face the same issues the OP faces. But I've successfully jailbroken my iP4 which is formatted for Mac.
..anyway, at some point I'm going to try the JB again on the recipients PC's to see if my theory is right.