interference with remote start from car?

I just installed a bulldog deluxe 500 onto a 2005 f650 yesterday, I have installed about 50-60 of these units and never had a problem...well on this truck, everything works perfect, remote start, door locks, everything except the 2 way remote part of it. After it starts or locks/unlocks, the remote does not show on the lcd screen whats going on, the little sattelite on the screen goes away, it thinks its out of range and it did not get a signal. So I thought, bad remote, so I programmed another brand new remote(had another new remote start system inside) and it works a couple of times and does the same thing...I have this system installed onto my truck and tried my trucks remote, same thing!! So I try the original remote on my truck and it works perfect???? I then swapped out the module, antenna wire, antenna, one at a time with the new one that I had, and with the one in my truck. Everything works perfect in my truck, but once its in the f650, no go. I have soldered all my connections, so there are good connections on the truck. I rechecked my ground a few times...I missed with this truck for about 10 hours yesterday and never got this problem fixed. ALL the parts work fine on my truck, but once installed on the f650 the remote will not get a signal back from the module saying its running, or the door lock status. I did work very briefly at the very beginning and nothing. I have had the antenna mounted in different spots as well with no luck. If anyone has any ideas on this please help me....is there an interferance on the truck somewhere not letting the signal get out of the truck back to the remote?? Its a auto salvage tow truck by the way if this helps, TIA

no ideas?