Http apache + Tomcat

I'm trying to use Tomcat via the jk connector. I followed the instructions
of ibm redbook with the only difference that I installed tomcat 4.1.27
because I didn't find the 4.1.24 anymore.

When point the browser to 8080 everything goes fine within Tomcat (including
Soap, Axis, etc) but at 80 it hangs. No errors, but it locks there.

This is what I see in jk.log:

> jk_uri_worker_map.c (460)@: Into jk_uri_worker_map_t::map_uri_to_worker
> jk_uri_worker_map.c (477)@: Attempting to map URI '/costa/CallSP.jsp'
> jk_uri_worker_map.c (558)@: jk_uri_worker_map_t::map_uri_to_worker, Found
a suffix match ajp13 -> *.jsp
> mod_jk.c (1708)@: Into handler r->proxyreq=0 r->handler=jakarta-servlet
r-notes=1073741824 worker=ajp13
> jk_worker.c (132)@: Into wc_get_worker_for_name ajp13
> jk_worker.c (136)@: wc_get_worker_for_name, done  found a worker
> mod_jk.c (497)@: agsp=80 agsn=hsvl01 hostn=hsvl01
shostn=hsvl01.sgr.sanpaoloimiwm.local cbsport=80 sport=80

Does anybody have some suggestions on what to do ?

Thanks.
Beppe.