RPC ncadg_ip_udp protocol with XP SP2

I'm trying use the datagram protocol ncadg_ip_udp with RPC.

I established the connection without any problems on Windows 2003. But

problems started when testing on Win XP SP2. It seems that the SP2 blocks the

datagrams.

I tried using authentication but it don't work. The only way succeded is

editing the RestrictRemoteClients registry key to be "0", but of course I'll

not do this in my application. Is there any other way to do this conncetion.

Here are articles about SP2.

http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2netwk.mspx

http://www.microsoft.com/technet/prodtechnol/exchange/Analyzer/209d02c4-877c-4128-8e22-30bcd4aae6d3.mspx?mfr=true

http://msdn.microsoft.com/security/productinfo/XPSP2/networkprotection/restrict_remote_clients.aspx

http://msdn.microsoft.com/security/productinfo/XPSP2/networkprotection/restrict_remote_clients_devimp.aspx