[exim] exim dies on the interrupted system call

Hi folks,

I can't understand how to deal with the dying exim. It dies with this in
panic log:
2010-12-25 23:17:44 [22683] failed to write to main log: length=115
result=-1 errno=4 (Interrupted system call)

I suppose that this is happening at the moment a high load on the file
system (backup of mailboxes). At least this was never on weekdays, only on
weekends, after or during the backup process. Other daemons running without
problems.

OS is FreeBSD 8.1-RELEASE, file system is UFS2 + gjournal (1Tb of free
space) on raid5 with adaptec 3805 controller. Exim version 4.72

Any suggestions?

Thanks in advance.

P.S. Sorry for my terrible english, i used online translator.

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WBR, Артём Каялайнен.