Key fob lock button not working properly

[big dave15]

My daughter got her Passat last week and I have been trying to get a spare key fob as it only came with one, and it will open the doors or boot everytime but it will only lock about once out of every 20 times or so.
The last owner said that it just needed a new battery but the battery has been replaced and its still the same, is this a common problem and can it be fixed as I was thinking that it maybe was dust etc under the button between it and the terminal ?
Meant to add that the replacement ( spare ) fob was £250 from our VW main dealer so I phoned around and found a auto key locksmith that has the fob in stock for £150 but the guy that programmes them is on holiday so she'll have to wait.

[big dave15]

I should have added that its a 2007 model with the 3 button fob

[Crasher]

Funny, my guy who does the same job is also on holiday but we are miles away! Anyway, that does sound like it needs a new key which is £132 from VW but then it has to be programed in.

[big dave15]

Crasher I phoned our VW dealers and with the fob programming and the blade key it came to £ 257 I near dropped when they told me

[Crasher]

There are lots of keys on the system but they all vary between £130 and £150 with the one I think you need 3C0 959 752 BA ZQG being £131.82 including VAT but this does not include the spare blade which is an additional £46.54 and as your other key will have one, I would live without!

[big dave15]

Thanks Crasher for the info, the funny thing was I could understand the price of the fob but I was shocked when I found out how much it was for the blade key.
But as I said the auto locksmiths supply the Fob program it and supply and cut the blade.