Seems quite a few are having this problem. My '04 started yesterday. I have installed a Viper 5900 and had the OEM bypassed somehow. Some notes, my key fob worked up until yesterday, lock/unlock etc. however if my Viper was still armed of course it would go off. That being said I walked out to my car yesterday to unlock it with my Viper and the Viper acknowledged the unlock by chirping yet my locks didn't move nor could I hear my trunk unlock like I'm used to. So I manually open it with my key in door, and OMG the siren. Obviously the OEM from under the passenger side of the hood 'Skream"ing at me. I'm going to try pulling fuse #35 today and see if it totally disable it. Otherwise while that is in "alert" mode having gone off, my tow/axle button beside my door unlock on the console blinks and when I turn the car to start, it only turns on, not over. I know I have a kill switch on my Viper, I've tried even setting it to Valet mode so it will not will not affect my diagnosing. Whats weird is after my OEM alarm goes off(meaning after its shutup and I reopen the door) there is a relay or something under my dash the kicks on and off at the rate of which my lights flash when I arm my system, but for 1-2 minutes. Making a slight clicking noise as you would assume. I'll post some feed back after I look at it today. BTW we need an iPhone/Android app for this site. lol

Malcolm