Problem with insurance quote

[Speed 3]

I have tried getting a quote from Footman James for my 2004 Tuscan following recommendations on here. However, they're refusing to even give me a quote until I confirm the Thatcham category of the alarm despite me saying it was factory standard for the year. Doing the usual research, I found this thread:

http://www.pistonheads.com/gassing/topic.asp?t=127...

I read that as no-one can say they have a Thatcham approved system unless they had the factory install removed and reinstalled by an approved installer. How have others got valid insurance from FJ or any other broker that asks the same question ?