Someone else brought up this problems in October 2013, and I've already sent a support ticket to Trapcode, but I thought I'd check here to see if anyone has found another solution.
Essentially, Trapcode Particular doesn't always let After Effects know that a parameter's value has been changed, and therefore that the Global Performance Cache needs to be reset. The only way to fix it is to purge the memory after every change. If you don't do this, you get a glitching effect as seen in the video & scene file that I've linked to below.
OSX 10.9.3 ; Adobe CC 2014 ; Trapcode 12.1.5