When I purchased a used '99 Infiniti I30t the dealership said that they had removed the original alarm system and installed one of their own.

For the past few weeks the remote keyless entry has worked flawlessly; however, for the past few days the remote trunk opener refuses to open.

The trunk opens fine with either the key or the trunk release button in the car, so the problem can't be the trunk safety mechanism becoming active.

Surprisingly, I have found an original factory remote used by the previous owner, and all the buttons on it works and it opens the trunk without problems!

What's going on here? Do I need to reprogram my remote or is something wrong with the alarm system?

I think I might just start using the original factory keyless remote full time now, but would there be any problems/complications?