4yr Revenue rule re. tax refund

Paid Revenue CAT of 44k+ in 2004 (April) and this week discovered in conversation that my solicitor in London had also paid inheritance tax to British Revenue on the monies received by me. The latter payment is less than my payment to Irish Revenue. When spoke to Revenue I was advised that a four year rule applies but the officer could not tell me whether this would be treated on a year basis or date of payment basis. I will submit request for refund anyway by end of 2008 but what are my chances of recovering double payment?
Williammmor

If all else fails with the Irish recovery do the UK have the same 4 year rule?

Thanks Sue Ellen I will enquire. However as I understand it the tax was due in UK as disponer was British citizen and lived in England all her life and related to UK estate. My solicitors actions were in accordance with British Revenue rules. The misunderstanding was on my side, based on the wording of the letter which accompanied the cheque. The solicitor who is now acting for me in the sale of a property in London advises that I need to follow up with Irish Revenue. Seemingly UK Revenue says there isa good chance of recovery under double taxation agreement. Thanks again.
Williammor