** This article only applies to the ArcGIS Desktop software versions noted above. This problem is corrected for ArcGIS Desktop 9.1 and subsequent releases of the software. **
According to version 6.5.1 of the European Petroleum Survey Group database, the false easting values for the projection files MGI M28, M31 and M34 are 150000 meters, 450000 meters and 750000 meters, respectively.
Replace the projection files installed with ArcGIS Desktop with the files at the links below.