Добрый день. У меня установлен FF 3.0.9  подключен к инету через прокси с недавнего времени стало появляться такая ошибка

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Что это такое и как исправить?

Вот список установленых дополнений
1.         AdblockPlus{1.0.2}.xpi   -- Ads were yesterday!
2.         BetterCache{1.24}.xpi   -- Removes anti-cache server response headers
3.         DownloadStatusbar{0.9.6.4}.xpi   -- View and manage downloads from a tidy statusbar
4.         ExtendedStatusbar{1.5.3}.xpi   -- A Statusbar with speed, percentage, time and loaded size (similar to Opera's one)
5.         FEBE{6.1}.xpi   -- Backup your Firefox data
6.         FastDial{2.22b}.xpi   -- (none)
7.         FlashGot{1.1.8.6}.xpi   -- Enables Firefox, Mozilla Suite, Netscape and Thunderbird to handle single and massive ("all" and "selection") downloads using the most popular external download managers for Windows, Mac OS X, Linux and FreeBSD (dozens currently supported, see Extension's Home Page for details). FlashGot offers also a Build Gallery functionality which helps to synthetize full media galleries in one page, from serial contents originally scattered on several pages, for easy and fast "download all".
8.         PasteandGo2{0.8}.xpi   -- Paste Text and Load/Search It Immediately
9.         PermaTabs{1.7.0}.xpi   -- Create non-closable tabs that stick around between sessions
10.         TabMixPlus{0.3.7.3}.xpi   -- Tab browsing with an added boost.
11.         TabScope{0.2.2.8}.xpi   -- Preview and navigate tab contents through popup.
12.         UnMHT{5.2.0}.xpi   -- View/save MHT
13.         Xmarks{3.0.2}.xpi   -- Bookmark Sync and Web Discovery