doors unlock when i remote start

I did a search and  found several other with this issue, oddly enough with the same model car as I have, but none had the exact set of variables that I have, so I decided to post. I just had a Viper 5900 installed on my 1996 Ford Explorer Sport. Everything works great, but the doors unlock when I remote start. The system does stay armed, but I don't like it that the doors unlock.

What can be done to fix this? Please keep in mind, my Explorer DOES NOT have a factory alarm or keyless entry. It did not come with one. Thanks!

That is what my installed thinks as well. He was genuinely perplexed by the issue, lol. I have to take it back in later this week.

And I have to give my installer props... I got my 5900 installed at a local Best Buy for two reasons: 1. They wanted less money than the smaller shops around me 2. The install bay actaully answers their phone when you call

When I called in today to inquire about this problem, the installer mentioned that he had been thinking about my install since this morning and that he couldn't help but think he forgot to program the alarm to ignore my dome light, as it stays on for about 30 seconds after I close the door and that it can cause my door/hatch sensors to bypass as they are all inter-connected. Sure enough, I did notice a few two-chirp armings with the alarm yesterday and today, but just ignored it cause it didn't happen every time. He was gonna call me after he finished his last install today, but I beat him to it, lol. :)

On another positive note, he thinks he has figured out a way to isolate my hatch from the dome/door sensors so it can have independent indication on my 2-way remote! We'll see how that works out, but I am quite hopeful.

Can't edit, so I have to add:

Actually there were three reasons I had Best Buy install it... The third was that I had $50 of Reward Zone certificates that I put towards it, lol. :)