I fixed it:
CSCsd82714 Bug: RTSP fails with Windows media player
Symptom:
RTSP stream setup is failing with "inspect rtsp" enabled for clients to a
statically translated server behind the firewall
Conditions:
Client on the outside is connecting to a server behind the PIX. The server
has a static configured and access-lists allowing this traffic:
static (DMZ,outside) 172.16.1.1 10.1.1.1 netmask 255.255.255.255
access-list outside_access_in permit ip any host 172.16.1.1
access-group outside_access_i in interface outside
Setting up a connection, the client information is passed to the server.
The server information is passed back to the host. The host then sends a
reset before the SETUP message is passed
Workaround:
Disable "inspect rtsp" within the configuration