Slawek,
I think that noone currently supports or tests Hunchentoot on Allegro CL. Its primary platforms are Lispworks, SBCL and Clozure CL. There are ports to other free CL implementations (ECL, CLISP), but I don't know how well they work.
If you are looking for a CL web server and want to use Allegro CL, consider using Allegroserve. It is included with Allegro CL and fully supported by Franz Inc.
If you still want to use Hunchentoot, you'll have to do some debugging work yourself. The locking problem that you described should be relatively simple to solve (but looking at the stack backtrace would be illuminating, use :zoom to see the backtrace). The segmentation fault that you've seen will be harder to debug. One you got it running, please send patches after having read http://weitz.de/patches.html
Cheers, Hans