Netbackup 7.5 with VCenter browsing virtual machine socket error 25

I have a Netbackup server 7.5  on Windows with a 6 ESX server 4.1 + Vcenter.

I've created a Policies to backup my VM some months ago and everything was working fine.

Now for an unknow reason, when I trying to add a new VM in my Policies, I've received an Socket error 25...

I was reading a lot of posts on the net and I tryed a lot of things but nothing work...

I was checking the name resolution, IP adresses, hosts name, hosts file, telnet, the credentiel for the ESX in the Netbackup console, nothing in the event vewer etc. Everything is ok...

I'm out of ideas... Where I can find, in Windows, a log or watever which I could see where's come the connection error?

Thanks for your time