HKS SSQ4 BOV Falls Off e60 BMW

[DiabeticGuineaPig]

Hey guys, installed the VRSF chargepipe and HKS SSQ4 BOV a couple weeks back and since then I've been having nothing but headaches. At first the rubber elbow connecting the chargepipe to the lower chargepipe blow open from underneath, creating a massive vacuum leak that is completely unseen.

Now, I've got the elbow squared away and everything is ship shape, even replaced all my vacuum lines just for the hell of starting fresh... but now whenever I go WOT in Map 1 of JB4 my HKS BOV flies off.

Any ideas why this keeps happening? Tonight I drove it and as soon as I nailed it in map 1 it flew off again. I've already had to buy 2 replacement o rings.

NOTE: I already made sure that I am putting the C Clip in with the slanted side up.