Windows 7 - starts multiple instances of TextPad

[BrooksL]

Just moved to Windows 7 32bit, running TextPad 5.4.2;

Though I have "Allow multiple instances to run" unchecked in the preferences configuration, Windows 7 still starts a new instance instead of a new tab when I double-click an associated file in Windows Explorer.

Augh! how dow I fix this? (yes, I set the config when only one instance was running)

-- BrooksL