What @GoSharks said
.
And in addition to what @knc1 said: do you even see the visual feedback of the JB install, or are you just restarting for the fun of it?
And to expand of the idea of trying to install something, there's a dummy package in the KindleTool thread if you want to try with something innocuous.
(FWIW, I do have a Touch running on 5.3.7.2, and I recently trashed it with a broken fonts-hack test package. Long story short, that gave me the perfect excuse to try a factory reset/full reinstall from scratch, and I definitely could download stuff from Amazon's cloud without any trouble [which makes sense, given that nothing we do should affect this [barring more intrusive stuff, like playing with the firewall or deep framework settings] ]).