Oh yea, Bumblebee could talk again at the end of the other movie, didn't he? I forgot about that. Sloppy sloppy on the writers part indeed.
Still in terms of action and humor the movie did very good for me. I liked the witty humor.
I guess you don't like it as much because you actually know the original Transformer comics and stuff. You have a better feel for the characters and tend to see things that are out of place from the original story. I don't know the original story though, so I just enjoyed the movie for what it was

.