Comment 10 for bug 220991

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6
Build Identifier: version 2.0.0.6 (20070728)

I have properly configured IMAP account NONE of my folders are marked for off-line use. I do not use off-line working.
When I'm getting new e-mail items, it happens sometimes that I cant open attachments. Associated application (e.g. MS Word or Adobe Reader) reports that file is corrupted or cant be opened. If there are a number of attachments, I usually cant open the last one. However I'm able to download attachments through web-interface on my e-mail server, and files downloaded in this way can be opened without any problems. I realized that in such situations attachment files saved from Thunderbird are shorter than the original files downloaded through web-interface or by another e-mail client.
By pressing "Ctrl+U" combination I can see the e-mail message source and an attachment base64 encoded and it seems that it is not completely downloaded.

I experience the above problem since the earlier versions. The same situation happens on different machines, running under Windows XP Professional Edition SP2 and Windows 2003 Server Standard Edition SP1.

Note that I do NOT interrupt downloading of the message. Deleting IMAP mail cache also as rebuilding index doesn't help. After the same e-mail is downloaded I cant open attachment and I cant open it after saving.

Reproducible: Always

Steps to Reproduce:
1. Send an e-mail with attachment to yourself (I sent an e-mail with 80 Kb .pdf attached)
2. Close Thunderbird if opened
3. Delete IMAP mail cache for the appropriate profile and IMAP account (I deleted all .msf files and containing directory)
4. Open Thunderbird, select Inbox for appropriate IMAP account
5. After message headers are downloaded, select the header of the mail you just have sent. Do not click headers of any other messages before, select exactly the one you sent. Do not interrupt downloading message.
6. Try to open attachment, in my case Adobe Reader reported that file is corrupted
7. Save attachment using "Save As" feature and compare its filesize with original file attached. In case of my 80 Kb PDF it was about 1-2 Kb shorter.
Actual Results:
Message is downloaded, but trying to open attachment by clicking it, or by using "Open" or "Save As" causes error in associated application. Message source (Ctrl+U) looks truncated.

Expected Results:
Message should be downloaded fully. User should be able to open attachments.