[Dovecot] strange fsync errors

[Hermann wacker]

Hi all,

I'm using dovecot since a few months and it works great.
But a few days ago some coworkers mentioned that they got
errormessages in their Mailapp.
I searched in the logfiles and found this:

Sep 14 12:07:35 Mailserv dovecot: IMAP(eckhard-ma-domain-com):
fsync(/home/eckhard-ma-domain-com/mails/.INBOX.0002-Druckangebote von
Druckereien.0002-schmerk
zwei_E-Mailverkehr/tmp/1189764455.P15962Q0M486676.Mailserv) failed:
Input/output error
Sep 14 12:07:46 Mailserv dovecot: IMAP(eckhard-ma-domain-com):
fsync(/home/eckhard-ma-domain-com/mails/.INBOX.0002-Druckangebote von
Druckereien.0002-schmerk
zwei_E-Mailverkehr/tmp/1189764466.P15962Q1.Mailserv) failed:
Input/output error

Mailserv:~# cat /var/log/mail.log.* | grep fsync
Sep 20 16:08:40 Mailserv dovecot: IMAP(aicher-fre-domain-com):
fsync(/home/aicher-fre-domain-com/mails/.Sent/tmp/1190297319.P5290Q0M979653.Mailserv)
failed: Input/output error
Sep 20 16:08:48 Mailserv dovecot: IMAP(aicher-fre-domain-com):
fsync(/home/aicher-fre-domain-com/mails/.Sent/tmp/1190297328.P5290Q1.Mailserv)
failed: Input/output error
Sep 20 16:18:24 Mailserv dovecot: IMAP(aicher-fre-domain-com):
fsync(/home/aicher-fre-domain-com/mails/.Sent/tmp/1190297904.P5290Q3.Mailserv)
failed: Input/output error
Sep 20 16:23:20 Mailserv dovecot: IMAP(aicher-fre-domain-com):
fsync(/home/aicher-fre-domain-com/mails/.Sent/tmp/1190298200.P5290Q6.Mailserv)
failed: Input/output error

The /home/ dirs are at a simple RAID 1 System, ext2 filesystem. No NFS
or other networkstuff.
I'm on a Debian Etch with dovecot  1.0.rc15-2

Any hints what this can be?

Thank you in advance
 Hermann Wacker