My 2c about tuning issues...
Since this is the semi-hollow board let's start with temp. and humidity changes. Depending on your guitar this can and does make a difference. Second is the sort of strings you use and the set up for each gauge. Change just a little and you will sometimes see dramatic differences in tuning. Then there is binding at the nut and saddle. I use Big Bends Nut Sauce for that. It works better then the old stand by of pencil lead and who can resist that name? :huh: Lastly, there is the way you wind the strings. Proper string winding makes a difference.
All that said, the Grovers that Gibson uses on their mid range guitars are not bad. Not great, but not bad.