I'm binding the dataView to a dataset (~400000 rows) and sorting it by a key (long type). I'm retrieving values from the DataView with FindRows(object key) which returns DataRowView[]. The problem is that rarely on Stress modes I get the following error: Source: mscorlib Message: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index The error has no sense since i'm not searching with the index of the array, so I suppose it's some FindRows inner exception. Did anyone had encountered it?