A whole folder of emails have disappeared.

Hello there, I recently decided to tidy up my emails and folders in Thunderbird. I made a new folder in 'Local Folders' with a couple of sub-folders. I then went through my hotmail inbox (in Thunderbird) moving about 500 emails to one of the three folders I'd created. Now, the emails I'd moved to the sub-folders are fine, but the emails I've sent to the parent folder are blank. This is important stuff! Hence why I backed them up to a local folder. The odd thing is, the folder says there are 186 emails in the folder, and I can see the little 'replied to' arrows, but everything else is blank. Please help! I've tried deleting all the msf files, and also tried copying all the blank emails to another folder. No results.