Look in your registry un HKEY_CURRENT_USER\Software\Xolox and see if "dropincorrectsegments" = "0" or doens't exist. In the preferences this is "Drop and retry incorrect segments" but I don't know if the registry keys are created if you haven' t been to your preference tabs.

If you are on broadband and are downloading from a fast host, it's concevable that you may get a large amount of the file in one chunk, then XoloX goes to put the peices together and they don't match up... When "dropincorrectsegments" = "1" I think XoloX does the check after the fisrt 2K has been downloaded to see if it can be synched with the prior segment.