Electrum for Windows 3.0.2 keeps renaming my wallet file

Every time I close Electrum, it appends .tmp.#### (where # is some random digit) to the filename of my wallet file. The next time I open Electrum, it can't find my wallet file and presents me with an Install Wizard window with the error

The file does not exist. Press 'Next' to create this wallet, or choose another file.

I can use the Choose button to navigate to the renamed file and it will open my wallet. After closing again, however, it appends another .tmp#### to the filename.

For example, if my wallet file is named default_wallet, when I close Electrum, the file is renamed default_wallet.tmp.9124. The next time I open Electrum, it can't find defalut_wallet and gives me the error. So I navigate to default_wallet.tmp.9124 and open my wallet. When I close Electrum, the file is renamed again to default_wallet.tmp.9124.tmp.4847 and the whole process starts over the next time I launch Electrum.

I have tried installing a fresh copy of Electrum, but the issue persists.

I'm using Windows 7 Ultimate 64-bit with SP1. I checked to see if I was missing any Microsoft updates for my OS. There are no updates being offered in Windows Update right now. However, since Electrum's download page says:

Note: Some old versions of Windows might need to install the KB2999226 Windows update.

I tried installing that update. When I did I received the message that the update is not applicable to my computer.

My Electrum for Windows installation was performed using the Windows Installer file from the Electrum download page. The problem also occurs if I use the standalone executable.

My Windows username contains only ASCII letters, no diacritical or Cyrillic characters.

Any ideas what I'm doing wrong to cause this constant renaming? Please let me know if I can supply any further information to help resolve this issue.

The issue names no source files or tests. Start by reproducing the wallet-file renaming on Windows 7 with both the installer and standalone executable, then trace the wallet file handling involved in closing and reopening. Done means the original wallet filename is preserved and Electrum reopens it normally on the next launch.