I'm sorry this remains such an issue for you. On my system I have an inexplicable bug where Maschine 2 won't work at all in Ableton. But I seem to be the only one. I've reinstalled both multiple times but no dice. Very frustrating.
 
I think FabFilter uses your video cards hardware acceleration for the interface so if they don't like the drivers that could be an issue. But you should be able to disable that and I don't really get why it would only be an issue when you're also using AD2.
 
I do know the Radeon 5450 is a legacy product and there is only a "beta" driver and a "last stable release". You could try switching between those, see if it helps? Or, if your mobo has on-board video, even try disconnecting it altogether to see if it is indeed the culprit. 
 
EDIT: I have a Radeon 6900M in my laptop by the way so I'm in the same boat driver wise but I don't know enough about their driver package to say if they're using essentially the same one or not. 

Did you update to Newburyport yet by the way? Or even .04?
 
I'm also puzzled by FF v2 not showing up in your other DAW. That would suggest something is wrong with the installation, except you say they work in Sonar as long as you avoid AD2?

OK, I rolled back the graphic card driver (by uninstalling all recently installed AT 5450 software) and got my stability back when working Kontakt 5 etc.  So the latest driver is not always the best ...
 
The FabFilter / AD2 problem persists. FabFilter support looked at crash files and projects, but could not reproduce. I suspect AD2 being the actual trouble maker now because I also got some funny messaging (AD2 itself while in use threw box requesting to be reinstalled) ...
 
Anyway, it not such a big deal. I know I need to keep FabFilter out of projects with AD2 and when getting into the mixing phase I need to bounce and delete AD2 before using FF. Fine with me.

I hate it when these things go unresolved. The FF guys are great with customer support in my experience. And I'm not just saying that because they're based like 5km from here. Shame they couldn't reproduce. Thanks for keeping us updated though.