My vote for this issue. The unresponsiveness of WinSCP when it tries reconnect is indeed quite annoying.
It hangs for about 20 seconds, and then instantly tries to reconnect which causes more hang. Its very hard to break the loop unless you taskkill it.
For how long does it hang?
When the host is mistyped or not responding the WinSCP GUI hangs.
I am running 4.2.7 on Windows XP 64 bit, but I have also noticed it in Vista 64 bit.
It hangs for longer when trying to connect by passing the IP address rather than the hostname.
I.E. Trying to connect to "1.1.1.1" will hang longer than trying "nowhere.noplace.com"