OK, I guess no one's had this problem.
After writing a curt email to Dension support I got some further assistance but it seems, alas, that the problem is fatal to my Dension iceLink.
It seems that somehow Rockbox has buggered up the iceLink, rendering it unusable with Apple inherent software despite having reset, reformatted and rebooted the iPod.
It still works with Rockbox however, but now I'm gonna have to think twice about buying a new iPod.