Forgot to post this -
Just to round this one up, I did receive my yellow slip refund on 24th November, letter dated 14th November (poor old pigeon takes 10 days to fly to Port

). It was the same as the other letter & refund as we already got to the house, no apologies for the delay.
The yellow slip "Refund Order" (Form No. L46/4-) are the ones done at Heuston rather than the Abbey St. office, it has a stamp on it:
Iarnrod Eireann Customer Relations
14 Nov 2006
Southern & Western
Heuston Station.
I'm going to try to cash it this week.
EDIT/UPDATE
Walked into Abbey St, into desk B, used my annual rail ticket as photo ID and got me fiver. Hurrah. An actual
'refund', all annual ticket-holders should get these instead of the discount vouchers.