"Only allow single instance of SuperPuTTY to run" not working in Version 1.4.0.6

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Check "Only allow single instance of SuperPuTTY to run" checkbox
2. Open serveral different sessions via CMD.
3. All will open a new SuperPutty session

What is the expected output? What do you see instead?

Each session should be opened in the same instance

What version of the product are you using? On what operating system?
1.4.0.6 on Windows 8.1 Enterprise (x64). It is working fine in 1.4.0.4 on the 
same device.

Br

Original issue reported on code.google.com by mich...@wingender.net on 14 Jul 2015 at 11:23

[GoogleCodeExporter]

Same on Windows 7 Professional (x64) SP1

Original comment by bith...@gmail.com on 6 Aug 2015 at 6:29