TOM2RN

I'm having a difficult time figuring this out. I recently bought a 99 Accord EX that didn't have remotes. I have purchased multiple remotes from two different companies and can only get one to work properly. The problem centers on the trunk release. One remote operates all the functions properly, but I can't get any of the others to operate in the same fashion. They just won't operate the trunk release. I have tried used OEM and aftermarket. Strangely, the aftermarket one operates flawlessly. The irritating part is that the same remote from the same company in the same order (I purchased two) does not work. They even exchanged the one that didn't operate correctly and still no go. My research has found that a 98 and 99 remote will operate a 00, 01, and 02 except for the trunk. Works backwards too....a 00, 01, and 02 remote will operate a 98 and 99 except for the trunk. I've given folks the VIN#, FCC ID, etc. and still no resolution. It shouldn't be the multiplexer or solenoid in the trunk because the one remote works without a problem. Any advice?