longer than a year for oil change?

[rh71]

My condition based service is telling me my next oil change will be 2 years from the last one I had. I thought it was supposed to light me up once a year regardless of miles? Did this change because I'm past the 4 year mark for some reason?

Jan 2008 (just purchased, first service)
Jan 2009 (low mileage oil change, 1 full year covered)
Jan 2010 (another low mileage oil change, 2nd full year covered)
Jan 2011 (another low mileage oil change, 3rd full year covered)
July 2011 (took it in for something else but CBS said I needed an oil change despite me doing the same mileage rate, and so they did it)
Jan 2012 (4th and final year done, no more coverage - they did a vehicle check/inspection, but since it had only been 6 months since last oil change and CBS didn't say anything, none was performed)

Today (being July 2012) I get an email from my dealer saying it's "likely" time to get an oil change since the last recorded in their books was July 2011. I check the idrive and it says I'm not due till JULY 2013 or 3800 more miles... that's 2 years since my last one. Even at this rate, I won't do 3800 miles for another 6 months or so.

I don't do 12k miles a year, but they've always given me oil changes once a year because I still do few but consistent mileage. Did something change perhaps because after Jan 2012 I'm no longer covered and they modify the plan?

Do I go for a change anyway since I'm paying for it regardless and ignore the idrive (have it reset too)? Or is there something I'm missing? I ask because if I ignore what it's telling me this time, what's to say CBS is even working properly - so I'm just trying to understand.