Everyone who's done actually has 102%.
I can't remember if that's on the Map or in ones Profile. It's wrong and the Developers know about it but it doesn't really matter, yes it's the profile thats wrong, the Map is where it's important and that will show 100% when done.
Have you checked every mini-map?
Scientists Castle, Underwater, Far Away Lands, Wonderland, Pyramid, Center of the Earth, Pirate Island, Haven Crypts and Twiggy Lake.
Don't forget that the main map also had a mini-update of 8 new squares all over the place some time ago, and that one of the mini-maps actually has one square on the main map.
All those 170 squares must be 100% which is the jigsaw puzzles and CI's, the only ones that don't matter are the optional friend zone that most people completed a long time ago, each only has a few CI's and no puzzle. 170 is the total number of squares, but you might have 10 squares from Christmas 2011 and 10 more from this year (2010's Christmas was completely different as was each and every other Event).
The profile should show something like the following:
Puzzle Pieces Found 4,930 ! -123-123 if you completed 2 Christmases
Puzzle Monsters Captured 190 ! -10-10 if you completed both Christmases
Customization Items Obtained 557 ! Everyone will have different numbers here, I have almost everything, minus a few new things from their second Easter event and minus most BW Club things after this April when I was hospitalized for 3+ months. I could count all the squares CI's from my spreadsheet but the profile does not distinguish one kind from another and only the ones from squares really matter, i.e. one does not ever actually have to play and holiday event at all.

No, being complete has nothing to do with being at Max Level.
Your map showing 99% means that you have missed something somewhere, not every one of those 170 squares is at 100%. look everywhere very carefully.
Look at your profile numbers for pieces & monsters, and compare your profile to someone like me in the top 25 of players, you might find the name of a monster you missed and that might point you to the correct zone.

Dave, your puzzle piece and monster numbers are right so all I can think is that you might be missing a CI somewhere and not see it. There are 173 squares, well 170 that matter. A few squares resist seeing, one Center of the Earth is on the main map, above twiggy lake is a mini map of only 1 square, I always forget to remember the crypts...
Or perhaps a fishing ci item but I don't think those matter.