HDT and Stacker could be a dangerous combination if you use a "Stacked" disk (a disk compressed with Stacker from Stac Electronics) that's been formatted with FWB's Hard Disk Toolkit on a computer running Apple's SCSI Manager 4.3. (SCSI Manager 4.3 only works on Centris, Quadra, and Power Mac models, and if you use one of those Macs, note that System 7.5 includes the SCSI Manager 4.3 extension in its default installation.) FWB Technical Support confirmed a report from Stac Electronics that SCSI Manager 4.3-compatible versions of HDT can cause data loss when used with Stacker. (The HDT 1.6 Read Me file alerts users to an incompatibility.) One solution is to not install the SCSI Manager 4.3 extension when installing System 7.5. (After installing the System, restart with extensions disabled and remove the extension.) On Macintosh models with SCSI Manager 4.3 in ROM, such as the Quadra AV systems and Power Macs, don't use "Stacked" disks if you formatted them with HDT 1.5 or later. FWB says a fix is in the works but will probably not be available until the next major release. [MHA]