Ever since Roxy was possessed by Nebula in episode nine, it occurred to a friend of mine (Darev from fanfiction.net) that Bloom really is bad at giving gifts or things in general to people. This is not the first time that Bloom has given something to someone with bad results.
The first time was during episode eight of season one: Day of the Rose/A Friendship Sundered. Bloom, back when she was fledgling fairy trying to get the hang of magic, was on a date with 'Brandon' (who happens to be mysteriosly blond...). Riven happened to be around and the two ended up in a argument that ended with Bloom levitating and emptying a pot full of water on Riven.
Later, as a way to apologize, Bloom gives Riven a new helmet that she recieved from Timmy (Knut in disguise) which happens to mess with him during the race. All the while, Bloom hears about the Trix's plan to compromise the race. She valiantly jumps into action chasing after Riven only to get yelled at. This ends up starting Darcy and Riven's relationship.
The second time was when she gave the White Circle to Roxy and well...we saw what happened there...
Nebula went power crazy using Roxy's body.
One interesting question is why did Bloom give a magical object to a person (Roxy) who has not a clue about magic? Irresponsible much?