AMO/Fx3.5/Incompatible Add-ons

Firefox 3.5.* Incompatible Add-ons

• .NET Framework 1.0
• Accessibar
• Active WhoIs
• Alexa
• All-in-One Gestures
• AutoCopy
• BlackX (theme)
• CA link advisor
• CA toolbar
• Clear Cache Button
• Code Burner for Firebug
• Colour Contrast Analyser
• Compete
• Copy Plain Text
• CSSViewer
• CustomizeGoogle
• CuteMenus - Crystal SVG
• DebugLogger
• Duplicate Tab
• Fast Video Download
• Flash Killer
• GaelSpell dictionary
• Google Gears
• Google Notebook
• Gspace
• HP Smart Web Printing
• HTML Validator
• hunspell dictionary in French
• LogMeIn Remote Access
• Media Converter
• Mobile Barcoder
• Mouse gestures redox
• Norton IPS 1.0 hotfix
• NoSquint
• Organize Search Engines
• Page Title Eraser
• Page Validator
• PageDiff
• PageShortcuts
• Passwordbank (Fingerprint passsword extension provided by Dell): compatible version
• Personal menu
• Print Context Menu
• Quick Locale Switcher
• QuickFrame
• QuickNote
• QuickProxy
• RealPlayer Browser Record Plugin 1.0
• Sage-too
• Save Image in Folder
• ScrapBook
• Server Switcher
• Stealther (replaced with Private Browsing)
• Tab Catalog
• Tab Clicking Options
• Tab Mix Plus
• TinyURL Creator
• Todoist Sidebar
• Tyba
• Undo Closed Tabs Button
• UnPlug
• Update Notifier
• YSlow 2.0.0b3

For incompatible video downloading extensions use Video DownloadHelper

Cnet also has an article: Firefox add-ons: Which work in 3.5?