ok try control panel-add/remove programs highlight DM, click change (if its there, uninstall if not)
DM box should pop up, click repair.
Let it do its thing.
Then re-boot PC.
Load up, click DM. let that load.
THEN plug in the BB. let that recognise etc.
And try the sync as before.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."