Flamming/Latency when Delay Comp ON and not "in the red"

I've been battling a frustrating problem during mixing for most of 2014. I'm getting drum tracks that start flamming and when I add/subtract plug-ins or make a change to an Aux track. I've accounted for Delay Compensation, accidental double-bussing, but still can't figure out why.



The temporary work-around? Rebooting Pro Tools completely and re-opening. However, once I make a change to an Aux the problem comes back.



Here a sound clip here:

https://hearmeshimmer.squarespace.com/track-latency



I've been mixing in Pro Tools for over 10 years and understand plug-in latency and delay compensation well, but haven't been able to get to the bottom of this issue. Any thoughts? I've cataloged this issue at the above link with more detail.





SYSTEM SPECS



Universal Apollo 16

To Mac Mini via Thunderbolt



Pro Tools v 10.3.6

Mac Mini Intel Core i7

OSX 10.8.3

Tracking to Glyph Drive via FW800.



ISSUE:



In reference to mixing a session in Pro Tools, making a change to an Auxiliary Track e.g. Kick Drum sub group feeding into an All Drum sub group, creates latency. This includes adding a plug-in to a sub group, moving/re-ordering plug-ins, or even adding a send to that auxiliary.



When adding a plug-in to sub group in with playback in progress, the latency effect can be heard. It's almost snapback-esque.



I have accounted for Delay Compensation (set at Maximum) and that tracks are not being accidentally doubled-bussed.



Again, this happens even with the changes made to an Aux aren't demanding an Delay Compensation adjustments such as re-order or adding a zero-latency plug-in to a strip.