ITunes Integration Problem
Occasionally Vuze has problems communicating with iTunes in order to copy transcoded files into iTunes to make them available for your iPad etc. When this happens a yellow warning triangle is shown against iTunes in the sidebar with a hover-over tooltip that says 'There appears to be a problem with iTunes integration'.
There are a number of causes of this issue.
One is that iTunes hasn't installed correctly - make sure iTunes runs successfully in the same user that you are running Vuze (i.e. that it opens and lets you browse the iTunes store and connects successfully to your device). If you installed iTunes in one Windows/Mac user and are running it from a separate user it is also worth installing it in the user you run Vuze in.
There was also a Vuze releated issue that was solved by an update to the Vuze iTunes plugin, available to all 126.96.36.199+ Vuze users (plugin version 0.2.6 for Windows, 0.2.8 for OSX). So make sure you are running at least 188.8.131.52
In the worst case you can manually copy the files to iTunes - right-click on the transcoded file in Vuze and select 'show in explorer' to locate it, then drag and drop it directly into iTunes.