Where can I find a list of the GPE commands that have been modified since the last version of dw-2000?

Every new Version of dw-2000 is accompanied with Release Notes (a PDF file on the CD) and within these there is a section titled "New and Improved GPE Command Quick Reference". This section supplies you with links to the relevant text that describes the syntax changes for each of the commands. The online Help reflects these changes also, so you can update your GPE scripts accordingly.