I have a large SharePoint 2010 list (~60,000 items) in which the list view threshold has been turned off. Recently, we've encountered the problem that exporting the list to Excel only yields a subset of the total number of items. Sometimes, refreshing the data connection will return 4,000 records to Excel. Sometimes it will return 20,000, etc. There doesn't appear to be any consistency in this, so my assumption is there there is some sort of network interruption happening.
Can anyone suggest some troubleshooting methods for this problem? I'm stuck.