I am sure it is a hassle keeping up with all the revisions of the IDE and compiler versions, but I am using the latest (or within a month or so) from Microchip....IDE v7.40 and C18 v3.03. I reverted to using the 18F452 for compatibility.
Still have the issue that OS_Delay()....which very well could be pilot error, due to the changes in the project build options that were required to get it to build. Anyway will keep working with it...it looks like a good product.