Wow, I didn't think that you would of had a problem with using DupiColor on the passenger side A pillar trim!
I was watching a Unique Autosports show on Speed TV and that Remy guy on that show had the same problem with painting a GMC Yukon Denali interior rear quarter panel trim. Same thing, the paint just flaked off and landed on the carpeting!
Very strange, I've never had a problem when using it on interior plastic trim panels!
Did you by chance try and use an actual plastic trim panel paint prep wipe/spray?
Failing that, I personally would try the "RustOleum" plastic primer and see if that works.
The only thing I would hazard to guess is (Please don't get pissed at me here!) the can might not have been shaken enough (Very unlikely I'm sure!) or the can that you have might be "Off" and paint itself old, flat, or just crap!
I feel bad now because I'm the guy who recommended this product to you in the first place!

If I were you, I would contact Dupli-Color and ask someone in their tech department. This is a direct quote from their website regarding their "Vinyl & Fabric Spray"
""Restore the color and finish to your car or truck’s vinyl, simulated leather or fabric interior. No need for a primer. It is flexible when it dries and won’t rub off, chip, crack or peel. Great for interior trim, seats, consoles, floor mats, dash panels, fabric seats and carpeting.""
And as you can see, it clearly states that "No need for a primer"!
Well, that as it turns out out is a load of Bull!
The only other thing I could think of is that you might need something along the lines of this stuff here:
http://www.canadiantire.ca/AST/brow...75046P/High+Performance+Adhesion+Promoter.jsp
I'm sure you can find a similar product at a local auto parts supplier in your area.
Or you may need to go to an automotive upholster and ask for some advice or perhaps a professional pre paint prep or???
Like I mentioned in my earlier post, I have never had any issues with Dupi-Color products. But then again, I have not tried to paint any interior KJ trim panels as of yet!