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