The BPEL editor automatically adds the "bpel" namespace prefix to a file if it does not already have this prefix defined. This causes the editor to show as "dirty" the first time it is opened, even though it hasn't been touched.

This is one of those minor annoyances that is difficult to fix because a lot of places in the code assume that the "bpel" prefix is always defined (that's why it's created if it doesn't exist