very slow rtmpt connection

We are using Amazon server. I looked at the requests when flash application makes connection to the FMS server, here is what I got:

1) I don't know why but first with this request we get IP address of our FMS servere in the Amazon cloud.

POST http://mymediaserver.mydomain.com/fcs/ident2 HTTP/1.1

We get IP adress - 10.49.6.128

mymediaserver.mydomain.com has complitly different IP adress

2) Then requests goes to POST http://10.49.6.128/open/1 HTTP/1.1

3)  Back we get error respond:

        HTTP/1.0 407 Proxy Authentitacion Required

         X-Squid-Error: ERR_CACHE_ACCESS_DENIED 0

         Status Code: 407

         Reponse Phrase: Proxy Authentitacion Required

4) Then request goes again to POST http://10.49.6.128/open/1 HTTP/1.1

5) Then this repeats several times (and takes time about 20 seconds)

>> Continuation or non-HTTP traffic

<< Continuation or non-HTTP traffic

>> Continuation or non-HTTP traffic

...

6) Then flash application makes request to  "mymediaserver.mydomain.com" not to the 10.49.6.128.

POST http://mymediaserver.mydomain.com/open/1 HTTP/1.1 Content-Type: application/x-fcs\r\n

7) We receive HTTP/1.0 200 OK. Now we are connected.

Maybe this can help to solve the problem?

As this problem is not only for me, it would be nice to actually hear some kind of explanation from Adobe why it is like this, even if there is no solution. Otherwise it is plain ignorance- and lets  not forget that FMS costs a lot of money. So maybe someone can bother give some kind of explanation?

I'm also facing this issue once my server was taken behind the hardware firewall (FortiGate 1000C) ... RTMP Connection opens in less than a second but for RTMPT it takes 30 seconds. When my IP was in public domain. I have checked the firewall setings of both i.e my Windows 2008 and that of hardware firewall with both port 80, 1935 are enabled but I'm too facing this problem.