Later revisions of the i1Pro are much faster than the older Revision A device. Since the iO table reads so quickly, the Rev A i1's are not able to keep up with the speed and will read patches inaccurately. You cannot upgrade your Rev A i1 to a later revision because the necessary changes are in the hardware. The following link will take you to a brochure of the latest i1 offerings so you can choose a device that will fit your needs.
In the meantime, you can use your i1 Rev A to read testcharts manually, or you can try reading your charts using the Patch mode in MeasureTool, which will read more slowly. The following link will take you to the installer for ProfileMaker, which includes MeasureTool and will allow you to read testcharts in demo mode.