My 95 is intermittently doing something similar too. Most of the time it works fine but every now and then it (remote or door button) will not unlock the doors. Sometimes I can get them to unlock if I push the lock button first, sometimes not.
My remote starter works off the unlock feature, push 3x to start. It still works after pushing unlock three times even when the doors don't unlock. I've had the remote starter on the car for about a year with no trouble. I don't think it'* the cause of my problem. Could it be the ground bars under the door seals that'* causing our troubles? Or a ground somewhere else?
1995 Bonneville SSE ...... L36 3800 Series II N/A V6, FE2 3.06 gears .......... 224K
2005 F150 Lariat Chrome Edition . Trition 5.4L Modular V8, 4x4 3.73ls gears .. 44K
2001 Wellcraft Martinique 2400 ....... MerCruiser 5.7L EFI Bravo III ............. 220hrs