When I download an attachment with Chromium in Lubuntu (11.04 or 11.10 and even earlier), and then try to click it in the list of downloads, it re-downloads (or maybe just makes another copy) with (1) at the end of the name. This occurs even if I close the browser, reopen it and try to launch the already downloaded attachment.
If I ask it to "show in folder", then it opens a tab and shows a web view of the folder rather than launching the folder in PCMan.
My main concern is the launching of downloaded files with the default program. Specifically, a video file with VLC (for instance). I'm helping out someone who is not able to navigate (let alone understand) a file manager in order to be able to launch it outside of the list of web browser downloaded files.
If I double click a downloaded file in PCMan, it launches as I would expect.
I also installed Google Chrome (as it would be very similar), but that had the same issue too. Changing to another web browser will cause other issues...unfortunately.
All of this works fine in Chrome/Chromium in the full Ubuntu or even Windows.