There is a general warning in this example. When you see a CAA logo or the phrase 'CAA approved', you need to be clear what the approval is for. The legislation that applies to aviation requires the CAA to approve many things - just because an organisation has an approval it doesn't mean that it's approved to do what you are going to use it for. Same applies to JAA and EASA.
If you really want to understand what the approval means you then have to look at the enabling legislation to see what the approval was intended to cover.
Or, if you can't be bothered with all that, I've always found personal recommendations to be very valuable (far more so that anyone's logo)!