Donations are given without return consideration. This lack of return consideration means that, in common law, an agreement to make a donation is an "imperfect contract void for want of consideration.". --wikipedia
Please stop abusing the words 'donate' and 'donation'. If you want to charge for your software then great! You deserve financial compensation for your efforts however to claim a non crippled version is 'donation' is a lie. You are trading money for a license to use your software.
So in conclusion, unless your 'donation' version includes no functional difference from you 'free' version, can the use of the word 'donate' in the title.