I keep trying to log into my host via SSH, "ssh cynagen@cynagen.com", and when I punch in my password, I get:

Last login: Thu Jan 11 21:26:36 2007 from 72.164.xxx.xxx
Could not exec shell '/bin/bash'
Connection to cynagen.com closed.

Now I used to be on /bin/bash until somebody hacked into my website and gained access to my virtual filestructure for my username, at which point the sysadmin (who granted me ssh and bash in the first place), freaked out and locked it down to jailshell. However, when he did this, I ended up starting to get these messages on every device I attempt to connect from, my work PC, my work MAC, my Pocket PC, my home PC, everywhere. He's blown my ssh account out of the water and put it back in, made the switch back and forth between bash and jailshell a bunch of times, but still no luck. Can anyone help us figure this out? I would love to have my SSH back if possible.

freaked out and locked it down to jailshell.
If you're still running a chrooted shell then it may well be an issue with missing dependencies. That's server-side, so his problem, not yours. If you mean "virtual filestructure" as in VPS of sorts then why not have him reload the O.S.?

I understand that, but most of this is going to be his problem, but seeing as how I get shell access for projects and such, I would like it to work, and I've always helped him out where I could, either locking down security, or whatever. This time I need to help him to benefit myself, otherwise I may never have shell again, and personally, i'd be REALLY p.o.ed if i couldn't test stuff without uploading it and then faking a shell with PHP, (which doesn't work anymore now that I helped him lock PHP out from shell stuff like that.)

OK. (IMHO the best way to start would however be a SELinux or GRSecurity-enabled kernel since those reinforce much more and allow much more fine-grained control than just that one aspect, but OK, his choice.) I've used Jail in the past and I never had problems I couldn't fix (when using the supplied tools and using them correctly). The first thing *you* should do is install Jail yourself on your local box so you understand the process. The first thing *he* should do still is to check and test if the chroot contains everything the shell needs. If he can't figure it out (I'm sure it's missing dependencies) he could build another jail and compare.