Lamp Replacement issue.

[Firestreak]

Alright, I have question for people who have replaced a lamp before. I got a replacement for a Sony HS51, and I got the recommended replacement bulb. Took out the carriage thingy that holds the bulb, and examined the old bulb.

Now the head of it is a smooth, square shape(with rounded corners). The replacement bulb has bumps that come out in the 4 corners, making it unable to slide in the same place all the way - ultimately, not allowing me to secure it tightly with the clips.

Anyone run into this before? The bumps don't separate. To test out if the bulb itself is right, I just taped the replacement into the carriage, put the clips to the side and fired the projector up again, and it works.. but I don't think it's as bright as it was before. Maybe my imagination, maybe it's not getting as much light because it's not secured as well. But I'm afraid that the heat of the lamp could cause trouble against duck tape.

I'm thinking maybe there's a method to take the bumps off, like a wire cutter or something, but they're only a centimeter out, and they're right by the glass of the bulb, which obviously I don't want to break.