This happened a while back, I was running 1.1rc3 up until today so I have no idea if it would have an effect. Sorry if its something that has been fixed. The error below was repeated many many times, I deleted the index so the user would stop getting disconnected (although I didn't hear any complaints). I have not seen this happen repeatedly in this manner to any other user yet.

Apr 15 11:26:48 boomhauer dovecot: IMAP(username): FETCH for mailbox INBOX UID 5003 got too little data: 5369 vs 38919 Apr 15 11:26:48 boomhauer dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Broken virtual size for mail UID 5003 Apr 15 11:26:48 boomhauer dovecot: IMAP(username): Disconnected: Disconnected bytes=139/145074 Apr 15 11:27:08 boomhauer dovecot: IMAP(username): FETCH for mailbox INBOX UID 5003 got too little data: 5369 vs 38919 Apr 15 11:27:08 boomhauer dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Broken virtual size for mail UID 5003 Apr 15 11:27:08 boomhauer dovecot: IMAP(username): Disconnected: Disconnected bytes=139/145074 Apr 15 11:28:50 boomhauer dovecot: IMAP(username): FETCH for mailbox INBOX UID 5003 got too little data: 5369 vs 38919 Apr 15 11:28:50 boomhauer dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Broken virtual size for mail UID 5003 Apr 15 11:28:50 boomhauer dovecot: IMAP(username): Disconnected: Disconnected bytes=139/145074 Apr 15 11:38:02 boomhauer dovecot: IMAP(username): FETCH for mailbox INBOX UID 5003 got too little data: 5369 vs 38919 Apr 15 11:38:02 boomhauer dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Broken virtual size for mail UID 5003 Apr 15 11:38:02 boomhauer dovecot: IMAP(username): Disconnected: Disconnected bytes=139/145074 Apr 15 11:38:52 boomhauer dovecot: IMAP(username): FETCH for mailbox INBOX UID 5003 got too little data: 5369 vs 38919 Apr 15 11:38:52 boomhauer dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Broken virtual size for mail UID 5003 Apr 15 11:38:52 boomhauer dovecot: IMAP(username): Disconnected: Disconnected bytes=139/145074

From dovecot-uidlist: 5003 W38919 S38270 :1208208981.7303_0.hill:2,S

-rw------- 1 username faculty 5236 Apr 14 17:36 1208208981.7303_0.hill:2,S

ls -l .snapshot/*/1208208981.7303_0.hill*

-rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.0/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.1/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.10/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.11/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.12/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.13/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.14/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.15/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.16/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.17/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.18/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.19/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.2/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.20/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.21/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.22/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.3/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.4/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.5/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.6/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.7/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.8/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/hourly.9/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/nightly.0/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/nightly.1/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/nightly.2/1208208981.7303_0.hill:2,S -rw------- 1 username faculty 5236 Apr 14 17:36 .snapshot/nightly.3/1208208981.7303_0.hill:2,S

mv dovecot.index.cache dovecot.index.cache.broken