Shim a toilet install -- how much is too much?!

First of all, this is a *great* message board. Thanks Terry & Co.!

My wife and I have recently tiled our main bathroom. What an improvement over the (suspect) vinyl flooring that was in there before! We're also about ready to install an American Standard Cadet 3 toilet due to the 10" rough-in that we discovered. Fun stuff! Unfortunately, there is ONE tile that is a bit wonky -- just underneath the toilet, if you can believe it. Figures. If I shim the back of the toilet, however, it feels fine. The catch? It looks like it's going to take 4 pennies on each side in the back to make it right. Is that too much? Another option, perhaps, is to grind some tile down, but I don't really want to get into that...

Thanks!

That should be okay. Polyseamseal caulk works well to cover up things like that and make the connection more sanitary (prevents 'misses' from leaking under the toilet). If you have spare tiles and caulk, you can remove the caulk around that tile, beat it in the middle with a hammer (wear safety glasses!), and pry it out in pieces, then replace.