I tried it now with a usb flash drive.
This is in /etc/mtab:
/dev/sdf1 /mnt/vl-hot/vl-hot vfat rw,nosuid,nodev,noatime,uid=0,gid=100,fmask=0111,dmask=0000,quiet,shortname=mixed,codepage=850,iocharset=iso8859-1 0 0
Should it say "exec" anywhere?
Without checking the option, it does say "noexec", but nothing is there with the "exec" option checked.