[Serusers] Problem with presence (400 response to subscribe)

Hello. I'm having problems with pa module. I try to SUBSCRIBE to a user's presence and I get a 400 response to this subscribe. Ser logs show: 12(10693) handle_subscription() entered 12(10693) parse_headers: flags=1581064 12(10693) parse_hfs(): Error while parsing headers 12(10693) handle_subscription(): Error while parsing message header 12(10693) handle_subscription about to send_reply and return -2 I'm using Ser 9.3 and Windows Messenger 4.7 for testing. My ser.cfg file looks like this: [...] loadmodule "/usr/local/lib/ser/modules/pa.so" [...] modparam("usrloc", "use_domain", 1) modparam("registrar", "use_domain", 1) [...] route { [...] if (method=="SUBSCRIBE") { if (!t_newtran()) { log(1, "newtran error\n"); sl_reply_error(); }; handle_subscription("registrar"); break; }; [...] I can post the whole file or the SIP logs if you need them. Does anyone know why it doesn't work? Isn't Windows Messenger compatible with pa module? Lots of thanks.