[dovecot] Dovecot splited fetch problem

[Hon]

Hello,

When I was trying out the IMAP server (using Mozilla as client), I have 
no success of receving mail with attachments.  Looking it down further 
I've found that Mozilla fetches the message in 10k blocks, and the 
server seems missed a couple of bytes at where the split occurs...

Mozilla start the fetch by saying:
* 413 FETCH (UID 827 RFC822.SIZE 106371 BODY[]<0> {10240}
-- snip to place of split --
zmmAWdUxYA6Aobczv4BguxSZGqdYs6ELNIpgjiPUdYLxsHy)
7 OK Fetch completed.
8 UID fetch 827 (UID RFC822.SIZE BODY[]<10240.10240>)
* 413 FETCH (UID 827 RFC822.SIZE 106371 BODY[]<10240> {10240}
6BilWYuUJGA4YeNYFJbI1gL

The resulting line (saved from Mozilla view source) is:
zmmAWdUxYA6Aobczv4BguxSZGqdYs6ELNIpgjiPUdYLxsHy6BilWYuUJGA4YeNYFJbI1gL
                                                ^^ Two bytes missing
Where the original is:
zmmAWdUxYA6Aobczv4BguxSZGqdYs6ELNIpgjiPUdYLxsHygZ6BilWYuUJGA4YeNYFJbI1gL
                                                ^^

I have tried this using Debian packaged (0.99.4-1) and self compiled 
0.99.5rc1.  Both exhibit this problem.