If the Open and Open Containing Folder entries are grayed then that means that the file is not or no longer in the original location where it was saved.

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

I have tried the download with Windows Firewall and Microsoft Security Essentials turned off. Same result - gray, no error message, no file in directory. I have tried download to multiple directories, drives and a thumb drive - no difference. If I open Internet Explorer to the same web site, it downloads with no problem.

I deleted downloads.sqlite and tried again, no change, still gray.

I went in to about:config and reset all the browser:download preferences to default. No change

I changed the download history settings

"# In Firefox 3.5 and above: Under "Privacy / History", select "Firefox will -> Use custom settings for history", then select "Clear history when Firefox closes", click the "Settings..." button and select "Download History" in the "Settings for Clearing History" window. "

No change

What is the current download location?

You can try "Always ask..." or choose another location (Desktop) to see if that helps.

• Tools > Options > General : Downloads : "Always ask me where to save every file"

I tried multiple download locations. I changed settings to Always ask.

I have since decided to reload the OS

This fixed the problem.

Thanks for your help, I posted this so it wasn't just left unresolved.