Found different figures for CPI than I used earlier, ie 3.1% and 1.1%:

So putting numbers on it, £75492 (PA Level 33) is outgunned by £76734 (PA Level 32 of £74427 increased by CPI of 3.1% (the September 2010 figure applied to pension calcs for the period April 2011 to March 2012 inclusive))?

PA Level 31 of £71928 from FY09/10 corrected by CPI of 1.1% (September 2009 figure) and again by CPI of 3.1% (September 2010 figure) could have been higher if September 2009 CPI was higher, but actually ends up as £74973.

No point using RPI though as we change to using CPI from April 2011. However, as I said before, given that we now have a pay freeze on and in April 2011 will change from using RPI to CPI, in my case, leaving in March 2012might just be the perfect sweet spot!!