Just a solution in case anyone has the problem I had…

After upgrading to Snow Leopard, I tried updating some apps - I went to the appropriate sites and clicked on the links to download the dmg files.

On each occasion that I clicked on such a link I was met with a new tab opening in Safari which was just blank - a dark grey page of nothingness.  Nothing I tried to download would work - even a ‘Download linked file’ in ‘right click’ context menu gave me nothing.

After some time poking around, however, I discovered that the integration with a download manager, iGetter, was the issue.  So I simply deselected the ‘integrate with internet browsers’ check box in the Preferences in iGetter, and bingo, all was right with the world.

So if you have problems downloading dmg files and have a download manager installed, you may get somewhere unhooking the integration between the download manager and the browser.

In my case, it was only safari that had the problem with the dmg files - camino, which I also run, had no problem.

Readingman, I have been unable to correct this error on my iMac. There seems to be no file connected with a download manager that could be the culprit. Have tried cleaning up permissions and eliminating any possible after-market software, but nothing helps. It’s almost certainly a Snow Leopard generated problem.

@purbookian - I have had this issue too and what solved it for me was to download Onyx and clear my caches - reboot and poof it works…

Disclaimer”  I don’t use any add-on products for Safari though..