Message "Remote file already exists" ( but it doesnt )

I am using WINSCP 4.22 (Build 480) in commander interface on WinXP prof SP3.

I want to copy via Drag&Drop a file app.war to a Sun Solaris 10 machine.
The file app.war does not exist in the target directory on Solaris. But WINSCP pops up a window saying:

Remote file 'xyz.war' aready exist. Overwrite?
New: 12587430bytes, 07.08.2009 10:05:55
Existing: 0 bytes, 30.12.1899 00:00:00

Watch the date & size of the "Existing" file !!!

Error does not exist in WINSCP 4.21 (build 428)

Hi Martin Prikryl,

please close this topic. After a little research in the forum I found that this bug is already on your buglist.
Sorry

Andi

As you have noticed, this bug is being tracked already.