Whoa, hold on…
There was never any 'free one year warranty extension' as you describe. If your serial number does not fall within the range of the machines covered by a three year repair extension authorization, then you never were covered. That program covered only select models within defined serial number ranges, and only for the symptoms described in the authorization, which were typically caused by the presence of defective capacitors. It was not a program which covered logic board or power supply failures for which other symptoms were obvious.
There is a second program, not associated with that specific repair authorization or that range of serial numbers, which covered other, later machines with a specific EMC code on the product label. That
REA program, which
may have covered your machine, ended in December of 2008.
If your machine was repaired in the last 90 days, the standard Apple parts and labor warranty for service applies. It was not covered by the earlier repair extension discussed here, as you've stated that it's our of range. It may, or may not, have once been covered by the second REA program, which has since expired. That program covered only specific 20 inch models with a particular EMC code, and only applied to replacements of the power supply,
not the logic board.
So, you've apparently got an 'apples vs oranges' argument here. That leaves you falling back on the 90 day coverage matter, and—if you are outside that window—leaves you with no coverage.