If I include an XISF file more than once in the Input Images for ImageIntegration I get a Windows error: "File I/O Error: Unable to open file: Win32 error (32): The process cannot access the file because it is being used by another process. : <name of XISF file>" With a FITS file there is no error.
Not a terribly important bug. Just a minor annoyance
Cheers,
Rick.