Thank you for your post.
If any background application is running a CPU intensive function, this would affect the entire OS and would not allow you to select that application. You will have to wait for the processing to release the memory so you can then select that application. In FileMaker Pro's case, wait for the next script step that isn't "CPU intensive". With your example, the next script step would occur after FileMaker Pro is finished with the "Perform Applescript" script step or finished importing the XML file.
In your previous post, if FileMaker Pro is active, holding down command-period will stop processing before the next script step is executed. If the "Perform Applescript" is being executed, the command-period will be recognized after "Perform Applescript" has completed.
Ok, I understand better, so basically you're saying that a single script step can't be aborted. As I said in my other post reply I think they can if proges window shows up.
But in that thread I wanted to illustrated that to me FMP as a Window management issue on Mac OS X, the window can be put rontmost but the menu bar would be the one from the previous frontmost window, you can't put FMP window frontmost when it runs intensive script, while I never had any problem to put frontmost other application windows even though they ran heavy cpu intensive operations.
FMP appears to me to have a window handling problem on the mac whil all the other mac application I worked with had no issue
Keep in minfd that I've a 6 core machine with 18 GB of ram, and SSD, so my os is not bogged down at all but the, alas singel core, FMP operation.