I noticed my group suffer the other day whenI slid mine out of the way for some testing.I can only assume that this is because my bow is tuned with the STS in place, so therefore I'd be inclined to think you need to "retune" your bow to the STS. Probably a nock high or low issue since the STS would appear to cause the nock to get thrown down because it only hits the string below the nocking point.

Rack-attack- nice to see you back here as well.

I'm no Rack-attack, but I did find the need to serve mystring on my Tribute with the newer style STS. Without the serving it started fraying the string rather quickly.