This is happening constantly to one of my Yahoo! accounts, the other synced fine. Both seem to have synced fully from what I can tell, but only this first one is throwing error reports.

Code:
Product name:    Zimbra Desktop
Product version: 7.1.2
Build ID:        10978
Release type:    GA
OS Platform:     Windows 7 x86 6.1
Time of event:   2011-11-13 23:00:10
Error type:      service.FAILURE
Item ID:         -1
Error summary:   Fetch failed for uid 40285

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Affected data - PLEASE REMOVE ANY SENSITIVE INFORMATION (size=0):
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Failure details - PLEASE REMOVE ANY SENSITIVE INFORMATION
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com.zimbra.common.service.ServiceException: system failure: Message data cannot be null or empty.
ExceptionId:sync-mbox-removedname@yahoo.com:1321254010529:8df98665617755f4
Code:service.FAILURE
        at com.zimbra.common.service.ServiceException.FAILURE(ServiceException.java:248)
        at com.zimbra.cs.mime.ParsedMessage.initialize(ParsedMessage.java:200)
        at com.zimbra.cs.mime.ParsedMessage.<init>(ParsedMessage.java:153)
        at com.zimbra.cs.datasource.MessageContent.getParsedMessage(MessageContent.java:58)
        at com.zimbra.cs.datasource.imap.ImapFolderSync.handleFetch(ImapFolderSync.java:917)
        at com.zimbra.cs.datasource.imap.ImapFolderSync.access$200(ImapFolderSync.java:63)
        at com.zimbra.cs.datasource.imap.ImapFolderSync$1.handleFetchResponse(ImapFolderSync.java:827)
        at com.zimbra.cs.datasource.imap.ImapFolderSync.fetchMessages(ImapFolderSync.java:859)
        at com.zimbra.cs.datasource.imap.ImapFolderSync.fetchMessages(ImapFolderSync.java:750)
        at com.zimbra.cs.datasource.imap.ImapFolderSync.syncMessages(ImapFolderSync.java:346)
        at com.zimbra.cs.datasource.imap.ImapSync.syncMessages(ImapSync.java:322)
        at com.zimbra.cs.datasource.imap.ImapSync.syncFolders(ImapSync.java:235)
        at com.zimbra.cs.datasource.imap.ImapSync.importData(ImapSync.java:163)
        at com.zimbra.cs.datasource.imap.ImapSync.importData(ImapSync.java:135)
        at com.zimbra.cs.offline.OfflineImport.importData(OfflineImport.java:100)
        at com.zimbra.cs.offline.YMailImport.importData(YMailImport.java:54)
        at com.zimbra.cs.datasource.DataSourceManager.importData(DataSourceManager.java:312)
        at com.zimbra.cs.datasource.DataSourceManager.importData(DataSourceManager.java:276)
        at com.zimbra.cs.mailbox.DataSourceMailbox.syncAllLocalDataSources(DataSourceMailbox.java:442)
        at com.zimbra.cs.mailbox.DataSourceMailbox.sync(DataSourceMailbox.java:480)
        at com.zimbra.cs.mailbox.DataSourceMailbox.syncOnTimer(DataSourceMailbox.java:409)
        at com.zimbra.cs.mailbox.SyncMailbox$1.run(SyncMailbox.java:257)
        at java.util.TimerThread.mainLoop(Timer.java:512)
        at java.util.TimerThread.run(Timer.java:462)

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