Always starts a new instance when started by a 64bit process

[zsimic]

When started by a 64bit process, Textpad does not respect the "Allow multiple instances to run" setting.

I want all my files open in one instance of Textpad (using the document selector to navigate between files). However, when a 64bit process opens a text document with Textpad, it seems that Textpad can't find the already running instance and creates a new one.

This is a problem. It should be easy to reproduce: just open several files in textpad from a 64bit process.

Can this be fixed please?

Also note: this only happens when the 64bit process opens the file using the default Notepad, and the option "Replace notepad" is checked in Preferences -> General -> Replace Notepad.

This is on XP 64bit Professional.