Duplicate message to server from soapui in 1 min

Hello,

I have a service that works ~65 seconds.
In soapUI i set Http parameter "socket timeout" to 100000 milliseconds.
And when I run my service from soapUI, I can see in HTTP log
that after one minute of waiting for response soapUI sends the second request to the server.
And on server side i also see two requests from client.

I set this parameter: -Dsun.net.http.retryPost=false in soapui.bat but it does not help.

How to solve this issue? How to prevent soapUI from sending duplicate messages?

Thanks in advance!