This is from 1.1rc5. I have no idea where the 2182 even came from, all copies of the dovecot-uidlist and all copies of the email in snapshots going back at least 2 weeks show the info below:

May 8 22:45:22 hill dovecot: IMAP(username): Corrupted index cache file /home/username/Maildir/dovecot/private/indexes/.INBOX/dovecot.index.cache: Corrupted virtual size for uid=956: 2182 != 4917

dovecot-uidlist: 956 W4917 :1208807110.M854034P88191.hill:2,RS

-rw------- 2 username egrstaff 4831 Mar 26 13:53 1208807110.M854034P88191.hill:2,RS