Button cannot be deleted as a process referencing this button exists

After some weeks of vacation, i was almost to the point of shooting a classical off-topic posting, in spite of all those blogtiquette rules that advise the savvy blogger of not doing so.

Luckily enough, i just found a sort of bug in Apex 3.0.1 (and earlier i believe), regarding the deletion of a button.

At any rate, before delving into the main topic, let me point out that this blog entry is heralding a new era for me, as it is the first one written on an Apple Mac, so now you can enroll me in the list of "ex-PC users" ;-)

And now for the main topic.

1. Create a blank page in an Apex application
2. Create a blank html region.
3. Create a button and call it SUBMIT.
4. Create an After Submit process of any kind and make it conditional on the SUBMIT button.
5. Change the process type to Before Header.
6. Try to delete the button:

Button SUBMIT cannot be deleted as a process referencing this button exists

If you open up the process definition page, you won't be able to see any properties telling that the button is linked to the button, but this is normal as it doesn't make sense to link a Before Header process to a button.
On the other hand, if you open the grid view for the process, you will actually find the missing property and it will report that button SUBMIT is attached to the process.
At this point you can clear the relationship from the grid view or alternatively change the process type back to After Submit and then clear the property from there.

And now i can go back to explore this exciting Mac world.