Comment 36 for bug 216699

Similar for me
-repeated attempts to use Firefox for apport report hung while reading through the first page of suggestions
-One CPU goes to full load and and stays there; when a kill instruction is given via System Monitor the firefox Icon will disappear but it will show as running for a while as a zombie.
Firefox has consistently been giving this problem for two days;
It is unusable now. Will hang on start up
Also makes other processes hang.

Might this be Help?
Error: [Exception... "Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFileInputStream.init]" nsresult: "0x80520012 (NS_ERROR_FILE_NOT_FOUND)" location: "JS frame :: file:///<email address hidden>/components/foxmarks-service.js :: logMoveFile :: line 331" data: no]
Source File: file:///<email address hidden>/components/foxmarks-service.js
Line: 366