Without a sample its hard to say what is happening. If you can provide a sample that demonstrates the issue I can try to see what's going on. That being said the records will be recycled by default so you could change the DataPresenter's RecordContainerGenerationMode from Recycle to one of the other options - e.g. Virtualize.
Thanks. Unfortunately I can’t provide you with our source. I’ll look into the RecordContainerGenerationMode as you suggested. I’ve been able to avoid the problem by slowing down the resort process. Seems as though the problem occurs when numerous elements are quickly moved around in the collection bound to the grid.