Re: additonal information
I haven't heard about the problem so far.
It is IE, or rather Windows, that decides what application to run to handle particular protocol. If you do not specify the protocol (http) in the URL, IE tries to guess it. For some unknown reason it thinks that proper protocol is SFTP or SCP and run WinSCP to handle it. Anyway, I do not think that it is problem of WinSCP, but rather of IE.
It is IE, or rather Windows, that decides what application to run to handle particular protocol. If you do not specify the protocol (http) in the URL, IE tries to guess it. For some unknown reason it thinks that proper protocol is SFTP or SCP and run WinSCP to handle it. Anyway, I do not think that it is problem of WinSCP, but rather of IE.