There is a new and improved gasket, as Toyota knows this is an issue and even put out a TSB.
Here is the TSB and the procedure for removing it.
http://ww2.justanswer.com/uploads/sk...rolla_0171.pdf
If you change it when the car is cold, you do not have to remove the coolant lines, just remove the throttle body from the intake manifold and there will be minimal coolant loss.
I dont know how stocking gaskets works at your dealer, but give them the new part number on the TSB to make sure they are not giving you a new old style gasket and sealant.
If you to 100% check to make sure it is the gasket before you do any work, start the car and spray car cleaner around the gasket area, if the engine RPM increases, you found the leak.