AFAIK, the devs do know about this bug, but here goes for the sake of reference.
Vladtmort does not currently give out the 25/25 scale quest even though you are entitled to it by having done the 1/1 scale quest via Avariatus and being between 25/25 and 49/49. Vladtmort happily keeps referring you to Avariatus (who actually says to go talk to Vladtmort once you're higher level at the end of the 1/1 scale quest).
/me waits patiently for the next patch which will hopefully fix this...
Qualin Midashan / Qnarl Sharptooth