It is possible that your anti-virus software is corrupting the downloaded files or otherwise interfering with downloading files by Firefox. You can try to disable the real-time (live) scanning of files in your anti-virus software temporarily to see if that makes downloading work.

See http://kb.mozillazine.org/Unable_to_save_or_download_files

Thank you for suggestion, I disabled my AVG and rebooted Firefox but I'm afraid it made no difference.

Despite all attempts and following the file http://kb.mozillazine.org/Unable_to_save_or_download_files I still am no further on. Wonder if anyone can make any other suggestions please

I have same symptoms with Firefox 6.0

I initiate download from site http://www.firstload.com/dl/Firstload.exe

the download asks to save Firstload-Setup.exe

I click on save, the download window appears with the download line for theis file but the download immediately shows canceled

when I click on the icon to restart the download the download appears to proceed to successful completion

when I double click on the download line to execute open the file (execute the exe) there is no response

when I look at the saved location the file is not present

if the save is stopped by something why does the download process not recognise an issue?

I have no active anti-virus but am running no script and adblock, neither seem relevant to this issue

btw http://www.firstload.com is one of those sites that takes credit card details provides free for 30 days then automatic debits thereafter, does it also have other unsavoury characteristics?