Well after hours and hours with both Verizon and Sling tech support.....trying to figure this out...I gave up.
I gave up on the WESTELL 7500 piece of junk. Went out and dropped another $99 on a new Actiontec GT704WGB at Best Buy....plugged it in, ran the set up...and BINGO! Streaming just fine on the 3G network now!
Seems as if there was somthing going on in that Westell 7500 Router that just did not work, not that anyone could figure out what the problem was!
Hope this helps others...