Permission Denied

Hi Folks,
I have successfully installed my parallel Zip Drive. I can mount it and
"cd" to it, write to it, but am unable to execute a program. The
following
is my setup:

~>ls -l /
drwxrwxr-x root root mnt

~>ls -l /mnt
drwxrwxr-x clay users zip1

~>ls -l /mnt/zip1
drwxr-xr-x clay users SP

~>ls -l /mnt/zip1
drwxr-xr-x clay users l01

~>ls -l /mnt/zip1/l01
-rwxr-xr-x clay users ex01.01

~>ls -l /mnt/zip1/l01/ex01.01
bash: /mnt/zip1/l01/ex01.01: Permission denied

I can copy the ex01.01 program to my home directory and it functions
fine.

I have read the man pages fs, fsck.ext2, e2fsck and they show no
solution
to this problem. Any help would be appreciated.
TIA
Clay Stapleton