Thanks guys. I gotta say though that it looks like the miters are getting more and more sloppy. Today I remeasured the Tablesaw alignment, and it still looked tight (.0015 or so). I did eventually find the culprit...Just somewhat flabbergasted as to what happened...
The throat plate is warped...By like a good 1/16th. I knew I was playing with fire not having a zero-clearance insert - but in looking at this box joints as they are now - I know what I'll be doing tomorrow