Compactenna...Grounded?

Today didn't work out so well. I did receive my Compactenna Tri-Band (2m/1.25m/70cm) antenna for my vehicle. I was previously using a Tri-Band standard vertical whip, but it doesn't compare to the 7.5" Compactenna. However, I can receive all day long but after some testing it seems I'm unable to transmit. The most likely culprit is that my connection is comprised of the following:

• 1x Compactenna NMO mount (DXEngineering)
• 1x NMO to SO-239 adapter
• 1x PL-259 coupler
• 1x SO-239 to 3/8-24 stud mount
• 1x Firestik Fire-Ring. 

My understanding is that the NMO mount requires a ground and the Fire-Ring grounds out before the antenna (see "Fire-Ring to K-4 Stud Assembly below).  So I'm not clear if this can work. Is it possible that simply trying to extend ground from the NMO mount to the ground side of the Fire-Ring mount would solve the problem?  Guess we'll find out.  In case you're wondering why I'm keeping the Fire-Ring it's b/c I need the option to switch to my Midland CB and FireStik II 5/8λ antenna.