.Wouldnt a cossie one be up to the job though as it is an adjustable one.
not nesseracly (?) are you 100% certain its working correctly? i would return to std setup to try to eliminate problems, sounds an odd problem not like one i have come accross yet and nor have i used that FPR coincindence maybe?
if it solves the problem great but if not its one more thing you can rule out.
it may pay for you to get it rolling roaded somewhere that way they can tell you exactly whats going on there.