Have you also looked into mtab to see if it is set there as well?
Thanks for your answer.
Even though the fstab line contained the "exec" option, I got "noexec" in mtab!
That lead me to think that maybe there was a conflict with the other fstab options.
Sure thing, "exec" needed to come after "user"
From the "user" option in "man mount":
This option implies the options noexec, nosuid, and nodev (unless overridden by subsequent options, as in the option line user,exec,dev,suid).
Thank you very much, Masta.
P.S.: Previously it didn't work as root or user.