Should warranties be capitalised?

I'm preparing the accounts & tax return for a client who's bought a laptop for £550 and then spent an additional £80 on a 3 year warranty for it. His other IT equipment is depreciated at 25% p/a using the reducing balance method, and I usually only capitalise items over £100, so my options seem to be to either include it in the equpiment account (but then the depreciation calc won't strictly be right), or to create a new account for it and depreciate it over 3 years (but then i'm not being consistant with the capitalisation limit), or I can include the whole amount in the p&l (which might look like a fiddle as I'd be overstating the expenses for the year).
I'd be very grateful for your thoughts & opinions on this!
thanks
jodie