Gammaray:
The principal restriction on the 6 year rule relates to 'inherent faults'.
For the first 6 months after purchase, any fault which occurs with the product is automatically deemed to have been 'inherent'. (i.e. there is an assumption, in law, that the problem was due to a fault in the manufacture of the product).
For the remainder of the 6 year period, the purchaser has to prove that the fault was 'inherent' (i.e. present when the product was manufactured and sold). Although this might sound rather daunting, most retailers will give the customer the benefit of any doubt. This is not, of course, due to any great generosity from retailers. It's simply that retailers are aware that, if the customer persues the issue through the Small Claims Court, it's likely that the court will rule (on the balance of probabilities) in favour of the customer. It's therefore far easier and cheaper for the retailer to repair or replace the item. (The retailer, of course, has the right to persue their own claim against whoever sold them the product).
There's a reference to the six year period in the BBC Watchdog link, above, and there's more about this on the DTI website, here:
http://www.dti.gov.uk/ccp/topics1/guide/sogconsumerguide .pdf
Chris