Yeah, as wrightme suggests, I'd need a little more info before condemning or even adjusting the rear suspension yet.
There have been times when I've \"tried\" to see if I could get the rear wheel to spin up coming out of a corner and I've yet to break it loose -- granted, I'm not trying too hard as I'd hate for the rear to step out on me.
Are you talking about getting loose as you're tipping in to a turn, mid-way, or on exit? Does it vary depending on the slope of the roadway -- do you see this worse on flatter corners? Does it vary depending on how much the bike is leaned? Is it only the rear that's getting loose? Any movement from the front tire? Where are you riding in the rev range, which powerband are you in, the lower or upper?
I'm curious as to how hard you're crackin' open the throttle. I'm not baggin' on you, just asking and trying to help here, but maybe this is a throttle management issue, rather than a suspension issue.
Of all the nuts on the bike, the most important one is the one holding the throttle.