After a little investigation I have found the quality campaign reference number for the replacement of the Electrical Distribution control box (MDI). It refers to units fitted to Volvo Penta D1B and D2B/D engines and was implemented due to possible starting problems and/or failures to deliver instrumentation signals.
The quality campaign number was 4877-1677, issued on the 27/02/08.
Quite often eligable serial numbers don’t receive the up-grades required under quality campaigns due to a change of ownership and and therefore the dealer/manufacturers loss of the ability to make contact with the current owner, I don’t know if this maybe what has happened in your case, although being commissioned in 2005 it is possible that it falls outside of the campaign serial numbers.
If you wish to find out if your engine is covered by the original campaign you can make contact with Volvo Penta via 01923 228 544.
Should your engine fall outside of the serial number range it is worth asking for a policy replacement free of charge or at least at a discount leaving you only with having to foot the cost of the labour. This kind of thing is sometimes done by manufacturers as a sign of goodwill where components fail well before their reasonable expectant life or in the event of a known problem outside of warranty.
Hope the above helps,