I am running 1.1.beta11 because I was having locking and coruption issues with indexes and mailbox on the latest release version. Some of my previous corrupted indexes caused an issue with 1.1.beta11:

Dec 20 21:25:40 ra dovecot: IMAP(bodil@mydomain.com): Raw backtrace: imap [0x47ef81] -> imap [0x47eca6] -> imap [0x42c3bc] -> imap [0x42f201] -> imap [0x42f324] -> imap [0x41d585] -> imap(imap_fetch+0x147) [0x41cb17] -> imap(cmd_fetch+0x1bc) [0x41686c] -> imap(cmd_uid+0x52) [0x419c42] -> imap [0x41a508] -> imap [0x41a5aa] -> imap(client_input+0x72) [0x41ab72] -> imap(io_loop_handler_run+0x106) [0x485746] -> imap(io_loop_run+0x1d) [0x484dbd] -> imap(main+0x401) [0x421f51] -> /lib64/libc.so.6(__libc_start_main+0xf4) [0x30af61d8a4] -> imap [0x414fa9] Dec 20 21:25:40 ra dovecot: child 4353 (imap) killed with signal 6 Dec 20 21:28:24 ra dovecot: IMAP(bodil@mydomain.com): file maildir-uidlist.c: line 840 (maildir_uidlist_set_ext_real): assertion failed: (rec != NULL) Dec 20 21:28:24 ra dovecot: IMAP(bodil@mydomain.com): Raw backtrace: imap [0x47ef81] -> imap [0x47eca6] -> imap [0x42c3bc] -> imap [0x42f201] -> imap [0x42f324] -> imap [0x41d585] -> imap(imap_fetch+0x147) [0x41cb17] -> imap(cmd_fetch+0x1bc) [0x41686c] -> imap(cmd_uid+0x52) [0x419c42] -> imap [0x41a508] -> imap [0x41a5aa] -> imap(client_input+0x72) [0x41ab72] -> imap(io_loop_handler_run+0x106) [0x485746] -> imap(io_loop_run+0x1d) [0x484dbd] -> imap(main+0x401) [0x421f51] -> /lib64/libc.so.6(__libc_start_main+0xf4) [0x30af61d8a4] -> imap [0x414fa9] Dec 20 21:28:24 ra dovecot: child 4385 (imap) killed with signal 6 Dec 20 21:30:08 ra dovecot: IMAP(bodil@mydomain.com): file maildir-uidlist.c: line 840 (maildir_uidlist_set_ext_real): assertion failed: (rec != NULL) Dec 20 21:30:08 ra dovecot: IMAP(bodil@mydomain.com): Raw backtrace: imap [0x47ef81] -> imap [0x47eca6] -> imap [0x42c3bc] -> imap [0x42f201] -> imap [0x42f324] -> imap [0x41d585] -> imap(imap_fetch+0x147) [0x41cb17] -> imap(cmd_fetch+0x1bc) [0x41686c] -> imap(cmd_uid+0x52) [0x419c42] -> imap [0x41a508] -> imap [0x41a5aa] -> imap(client_input+0x72) [0x41ab72] -> imap(io_loop_handler_run+0x106) [0x485746] -> imap(io_loop_run+0x1d) [0x484dbd] -> imap(main+0x401) [0x421f51] -> /lib64/libc.so.6(__libc_start_main+0xf4) [0x30af61d8a4] -> imap [0x414fa9] Dec 20 21:30:08 ra dovecot: child 4397 (imap) killed with signal 6

I removed the index files for that mainbox and that error went away, but it caused another error: Dec 20 21:45:29 ra dovecot: IMAP(bodil@mydomain.com): file_dotlock_open() failed with file /mailindex/mydomain.com/bodil/.INBOX/dovecot.index.log: No such file or directory

I had to recreate the .INBOX folder manually and all was great. The funny thing is it had already created all the other folders in the mailbox....