[Dovecot] uid=error and BUG: Unknown internal error dovecot 2.0.13

[Robert Schetterer]

Hi Timo,
i have a few ( not really many )
errors like this with lmtp

Jun  7 09:41:23 mail02 dovecot: lmtp(11034, user at user.de):
DELlOoq+7U0aKwAAZA6IsQ: msgid=<4DEDD502.705020 at ameriton.com>: save
failed to INBOX: BUG: Unknown internal error

Jun  7 09:36:22 mail01 dovecot: lmtp(26456, user at user.de): save:
box=INBOX, uid=error,
msgid=<OF671FDBE9.DD479224-ONC12578A8.00282832-C12578A8.0029C38D at hella.com>,
size=7192

any idea ?
is it critical, possible to loose mails with this ?

system are two postfix/dovecot servers with drbd and ocfs2 store
behind load balancers

-- 
Best Regards

MfG Robert Schetterer

Germany/Munich/Bavaria