Version 2.40 is pretty old. If for some reason you can't upgrade to the latest
version, then you might try contacting MeLabs directly to see what changes
they made to the 18F I2C library routines.

Look here http://www.microengineeringlabs.com/...pgrade.htm#pbp

They've had a LOT of updates since v2.40 for the 18F series. Well worth the
few bucks for an upgrade if you're using 18F parts.