We're testing a theory here at Betanews: that a problem with the most recent revision of Sun's client-side Java VM may be preventing Microsoft's Download Manager app from enabling downloads of the latest Windows 7 beta for some users. Those tests are ongoing, and we'll keep you apprised of progress.

UPDATE While some testers have already found success in downloading the gargantuan Windows 7 .ISO DVD image file, others are like us and have had a truckload of problems. There may be any number of reasons why that have nothing to do with Microsoft's servers, and one we're tracking down has to do with the most recent Java 6 Update 11, which is used for the Download Center applet, used when trying to download the .ISO using both Firefox and Internet Explorer.

Our Firefox 3.0.5 on multiple systems can actually crash during the attempt; IE7 simply hangs. But later in the day, we noted that rebooting Firefox can automatically relaunch the download attempt, and that time (and only that time), it'll actually get somewhere. While the download stalls later (this time, perhaps for server-related reasons), we do get off the ground.