Hi,
I tried your vi: I don't get any error message after removing the disk but LV7 keeps on accessing the drive at regular intervals even if you stop the vi and close it!!! This is not supposed to happen.
The only way to stop it is exit LV7.
If you don't use the file dialog and you wire a full path, you don't get any problem.
I also created a very simple vi that conditionally writes a text file on a: and I got the same behaviour.
This problem occurs only with LV7, I tried the same examples in LV6.1 and everything was fine.
If anybody wants to try I attach this simple example,
Alberto