If its the CP trigger. I also modded an ion a few weeks back and slapped one of these on.
I found that not only did it have a slight sideways movement, it also slowly unscrewed itself at higher rates of movement. I tried a few things. But, for myself, I found if you put a really tiny amount of thread lock on the threads after youve screwed it in. (the ones that poke out of the otherside) it not only solves the movement on the trigger, but also the unscrewing (afterall thats what thread locks for).
Just to clear things up for anyone else -
Ive had a few people recently ask me about thread lock (lock tight, pro lock, etc.). Common misconception seems to be that it is permenant, i.e. does not move when put on. Its not like superglue, its only there to stop the screw un-screwing itself under vibration.
Hope this helps!
JamesK