You can check the following url for slow WMV download process
http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_tech_note09186a00804c8b9f.shtml
http://www.cisco.com/univercd/cc/td/doc/product/multisec/asa_sw/v_70/cref_txt/gl.htm#wp1573329
When you use RTSP inspect command, there are the following Restrictions and Limitations:
The security appliance does not support multicast RTSP or RTSP messages over UDP.
PAT is not supported with the inspect rtsp command.
The security appliance does not have the ability to recognize HTTP cloaking where RTSP
messages are hidden in the HTTP messages.
The security appliance cannot perform NAT on RTSP messages because the embedded IP
addresses are contained in the SDP files as part of HTTP or RTSP messages. Packets could
be fragmented and the security appliance cannot perform NAT on fragmented packets.
You can configure NAT for Apple QuickTime 4 or RealPlayer. Cisco IP/TV only works with
NAT if the Viewer and Content Manager are on the outside network and the server is on the
inside network.
Media streams delivered over HTTP are not supported by RTSP application inspection. This
is because RTSP inspection does not support HTTP cloaking (RTSP wrapped in HTTP).
I guess your media application hits one of the above Restrictions. So when you remove
rtsp inspect, your media stream can pass PIX 7.0.
