IF you have NTFS file system corruption it is not a Thunderbird issue, it is a windows issue as the integrity of the file system is one of the things Windows is supposed to manage.

A corrupt file system by default means all bets are off as any file that Thunderbird or any other program writes could be placed anywhere at all. Recovery is also problematical in most circumstances. But there a utilities out there that I have used successfully over the years to at least recover fragments of the corrupt files..

Thank you Matt for your reply! The connection between the NTFS.sys message and the crash report from Thunderbird (correction: ...PAGE_ERROR should read ...PAGE_ERROR_READ) is not absolutely certain. Since I see no trace of the folder files, only their corresponding .msf-files, in the "LocalFolders" folder, it is probably difficult to apply a utility for recovery?

Tools like these http://www.ntfsundelete.com/ look for all deleted files and let you make some educated guesses as to which are the ones you want.

Thank you again Matt for making me aware of this utility! I have so far not detected any other problems with the file system than the two folder-files missing in the Thunderbird LocalFolders folder. This appears to imply that there is not a more widespread corruption of the file system that happens to have affected the Thunderbird files.