Well, I've done some more digging and discovered some unusual results.
I have 3 different builds of eyeBeam 1.5.
188.8.131.52 build 42985 - STUN works
184.108.40.206 build 44222 - STUN works
220.127.116.11 build 44360 - STUN does not work
Unfortunately, I'm using the last build which is not working. I'll contact my sales rep and try to get an updated build, but I though you might find this information interesting and helpful. Thanks.