I tried to install uqm on my new Vista, the installer downloadet everything, but stops responding when it tryis to download uqm-0.6.0-voice.uqm, even thougt I was certain it had done that already.
If the installer doesn't download the main content package, the voice package or the 3DO music package properly, you could try downloading it manually and putting it in the same directory as the installer before running the installer. When doing so, make sure the file retains its original name.
Note that the voice package is huge compared to the rest of UQM, so downloading and installing it will take quite a while.