General :: CentOS 5.4 - Bash Script Exits SU Or SSH Session

I am using CentOS 5.4. I created a bash script that does some checking before running any commands. If the check fails, it will simply exit 0. The problem I am having is that on our server, the script will exit the su or ssh session when the exit 0 is called.

#!/bin/bash
# check if directory has contents and exit if none
if [ -z "`ls /ebs_raid/import/*.txt 2>/dev/null`" ]; then
echo "ok"
exit 0
fi

Here is the output:
[root@ip-10-251-86-31 ebs_raid]# . test.sh
ok
[russ@ip-10-251-86-31 ebs_raid]$

I was removed from my sudo session, if I wasn't in the sudo session, it would have logged me out of my ssh session. I am not sure what I am doing wrong here or where to start.