Firefox downloads fail, yet other browsers succeed

System: Windows Home Premium, SP1, 64 bit, ASUS laptop K52F

There are many postings on similar Firefox download problems, but none seemed to fit my situation.

I have 2 accounts on my laptop, one is a standard user account and one is an Administrator account. This problem occurs in both accounts. I have no problem using IE or Chrome to download items to my desktop. When I attempt a download with Firefox, the download proceeds with the entire file being downloaded, but then the word "Failed" appears in the Firefox download screen and sure enough the download has failed. Note that the problem occurs on the majority of downloads but not on every download. I can find no pattern as to when it works or fails. The file type (eg: exe, pdf) has no impact on the problem. Since downloads work with IE and Chrome, the problem is probably not with the Windows firewall or with Avira anti-virus. Perhaps one of the add-ons is causing the problem? If not, what could it be?

I have the following extensions in Firefox:
ADBlock Plus, Blur, Disconnect, Google Analytics Opt-out Browser Add-on, Video Download Helper, WOT

I tried disabling Video Download Helper - no impact.

The following plug-ins are set to always activate:
Shockwave Flash, Primetime Content Decryption Module by Adobe
All other plug-ins are set to either "ask to activate" or "never activate".

Thoughts?

 

Even with ALL addons disabled, the downloads still fail. What the heck is going on???????????

 

I solved the problem. I had chosen the Desktop as the Firefox download folder. When I changed the download folder to "Downloads" (e.g.: C:\Users\account name\Downloads, the downloads worked. I tried this in both accounts and the solution worked. Have no idea why this should solve the problem. I have write permission to my Desktop folder and IE & Chrome have no problem downloading to Desktop. Very strange, eh? Do you have an explanation?