Alarm stopping car from starting?

[shag]

I have a 1993 LE 190E, I am the third owner and the car only has 113,000 miles on it. It was running perfectly ever since I got it (but that was only yesterday lol) I test drove it and no problems what so ever. And it ran perfectly all day today. I was taking pictures to show my relatives out of state and was trying to get some of the trunk. The trunk is tricky you have to like turn it push it in then pull out and turn to middle. It took me a while to get it down and I had been turning it back and forth for about 5 minutes doing it quite a few different ways. I then finally got it open with a little help from my brother. I then procedded to lock it all up again and then decided to move it into the driveway. So I went to the drivers door unlocked it and got it. When I tried to start it all electronics go on lights are bright radio works, everything but the car doesnt even turn over. You can hear the ignition or starter trying to start and the fan moves a little but no turn over. My friend brought his mercedes over (different make and model) and showed me what happened when his alarm was armed and he tried to start it and it was the same exact thing mine was doing. But after he closed his car back up and unlocked it it started up fine. I'm no technician and I am lost as what to do. He came over and fiddled with it and I played with the trunk some more but to no avail. We also tried jumping it just in case it just didnt have enough power to start, but that did nothing either. I am no technician so any advice you guys have is greatly appreciated!! Thanks in advance.