[Dovecot] raw backtrace in masses

[John Adams]

Hi

I've got huge amounts of

May  3 15:47:37 host dovecot: [ID 583609 mail.error] IMAP(user): 
close(/home/user/Mail/R-Help.lock) failed: Disc quota exceeded
May  3 15:47:37 host dovecot: [ID 583609 mail.error] IMAP(user): Raw 
backtrace: 0xb0e58 -> 0xb0894 -> 0x552b4 -> 0x55508 -> 0x55774 -> 
0x55d9c -> 0x5759c -> 0x57ad0 -> 0x713cc -> 0x64284 -> 0x57be0 -> 
0x71178 -> 0x6841c -> 0x76a38 -> 0x76a6c -> 0x25a08 -> 0x2afd4 -> 
0x2bee4 -> 0x2bea0 -> 0x2c1f8 -> 0x2cb4c -> 0xb9450 -> 0xb8d00 -> 
0x35294 -> 0x246e8
May  3 15:47:37 host dovecot: [ID 583609 mail.error] dovecot: child 3892 
(imap) killed with signal 6 (core dumps disabled)
May  3 15:47:49 host dovecot: [ID 583609 mail.error] IMAP(user): Raw 
backtrace: 0xb0e58 -> 0xb0894 -> 0x552b4 -> 0x55508 -> 0x55774 -> 
0x55d9c -> 0x5759c -> 0x57ad0 -> 0x713cc -> 0x64284 -> 0x57be0 -> 
0x71178 -> 0x6841c -> 0x76a38 -> 0x76a6c -> 0x25a08 -> 0x2afd4 -> 
0x2bee4 -> 0x2bea0 -> 0x2c1f8 -> 0x2cb4c -> 0xb9450 -> 0xb8d00 -> 
0x35294 -> 0x246e8
May  3 15:47:49 host dovecot: [ID 583609 mail.error] dovecot: child 4277 
(imap) killed with signal 6 (core dumps disabled)

The backtrace is always the same content.
is this a disc quota problem?

Dovecot is 1.2.11, managesieve patched.

Thanks