BizTalk SetTimeout

Hello, 
In my orchestration I have a send/receive ****t towards a web service. 
After I send an xml request, sometimes I have this message (in the 
windows event) when receive response : 
" The adapter failed to transmit message going to send 
****t "http://localhost/wsSabre/wsSab­re.asmx".
It will be retransmitted 
after the retry interval specified for this Send ****t. Details:"Timeout 
operation." 

I have read that I must set the Retry Interval. I have found this 
parameter in BizTalk Explorer, but when I change value, and recompile 
the project, this value is always set to the value "5" (minutes). 
I can't change it! 

How can I do? 
thanks for all response! 

Francesco