Windows error message when opening files

[barbiedoll]

I just upgraded to Textpad 5.4 on Windows XP and I'm getting the following error when I double click my text file (.sqr).

Windows cannot find 'I:\user\adpq2.sqr'. Make sure you typed the name correctly, and then try again....

Textpad did open the file first, then minimized the textpad window and then the error message displayed in a new window.

Any help would be appreciated.