JDownloader & Vista, problem updating automatically

Well, since new version i have problems when updating using the jdownloader system, it says there are X updates available, i accept to install them and it does nothing. The Jdownloader start window is still there and javaw runs normally but update doesnt happen.

If i click on Cancel Jdownloader starts ok and if i update manually downloading it again and replacing files it works well, but to the date i haven't been able to update it the right way.

I'm running Vista 64 bits btw.

What happens if you execute jdupdate.jar (JD must be closed)?