When syncing from a device (ipad or laptop) custom apex and or a sync too large can cause the sync to the sever to fail. It shows up as something like this: System.LimitException: SVMX:Too many SOQL queries: 101. It is a known defect.
The records that are in the sync don't get to the server and the error prevents further syncing. Usually on the ipad a reset app is needed to clear the files and all the data is lost. If these records that caused the error could instead go into the sync conflicts section they could be released one at a time preventing the soql error and preserving the data. This would go a long way in preventing data loss headaches from users and allow for further customizations without fear of this error. Alex Langston