Winscp corrupting PuTTy key ?

Winscp opens. I attempt to do Sudo on putty (long story -) CAn't. Close Winscp.
open putty.
connection unexpectedly closed.
Cannot use putty.
Nothing in log except server unexpectedly closed connection.
Remove pkk from registry.
Rebooot server.
putty connects (reconstructs key?
Open Winscp
and the story repeats itself. PuTTy works when winscp not initiated.

Note I cannot access the control panel on server (same long story..sad) and cannot transfer or files unless I get scp working...so any thoughts?

May you are allowed only one simultaneous connection to the server.