I run vista on a new laptop.
I played ddo and it worked fine for a while
then mysteriously it stopped working?! After reading the forums with no sucess in solving this problem I found the solution!
Try this first:
Open internet explorer then file> make sure 'work offline' is not checked!!!
I use the opera web browser mainly and accidently selected work offline in IE.
the lesson is twofold:
1) DDO can think your not connected to the net if it precieves you as working offline
and
2) internet explorer is stupid.
this worked for me, hope it helps someone!
-PhantomRx