Downloads - "Mounting Failed"

[dazednconfused]

Everytime I try to download an app (DivX or VLC) the file seems to download normally then in my 'download window' it says "Failed to Mount" once the download has finished... an icon appears on my desktop such as "DivXInstaller.dmg" but when i click on it then a window opens saying "No such file or directory"

What's going on?!

 

[artov]

The .dmg file is OS X's disk image file. It contains image of a disk, which
should be mounted as a virtual disk. If you get messages "Failed to Mount",
most likely the file has somehow damaged during transfer.

You might like to try to build a .dmg file your self, to check if the problem
is in mounting. Start Disk Utility, click New Image icon, give it name and
save where you normally download your files. Give it some size and click
Create. You should get a .dmg file, which sould be mounted as a disk.
Open the disk icon, and you should see an empty disk. Copy some files,
close the window and unmount the disk. Then, double click the .dmg file.
If this worked, the problem is most likely on your downloading.