Levi,

If you have it setup the way you described I would lean very heavily towards the fact that you fixed an unknown boost leak to cause the boost increase shown on the gauge after wrapping.

Since you have the waste gate referenced to the compressor housing and the boost gauge referenced to the mainfold you can have 10psi (just an example number) at the compressor housing and some value less than that (ignoring normal pressure loss through the IC, etc) at the intake manifold via boost leaks. Let's say you were losing 2psi via leaks, you would see 8psi on the gauge. When those leaks were fixed the boost you were losing now makes it to the manifold and thus the gauge reads 10psi. All the while you did nothing to the waste gate to change boost settings.

My .02