problems with putty

from when i installed the new 5.20 (build 3157) i have problem with putty:
when i call putty from winsc the connection start but immediately stops and when i try to send a char (via keyboard) putty closes.

launching putty as standalone all runs ok.

can you help me?
can i help you?

thanks

lorenzo

Can you attach PuTTY event log for both scenarios?