Thanks Joe S for the links, I already looked at most of Microchip data sheets and Application notes. Lots on M2510 but not much on ECAN.

Just checked the 18F4580 Errata, but there is nothing in there wrt CAN.

INSE, I just had a look at the 18F248 data sheet and the CAN module has the same basic register set as the 4580 ECAN module. The CAN module is more appropriate to my requirements and my code should not require any major changes to run on 18F248. I have ordered a few of them today - did you have any problems or did you find everything pretty straightforward ?