DAE 5.1.1 CS 1 contains two fixes:1. Support for Removable/"Hot-Swap"Media for Pro Tools TDM Mac & Pro Tools LE Mac. Adding removable SCSI, hot-swappable SCSI or Firewire media to a Pro Tools 5.1.1-based system or earlier, requires Pro Tools to be quit and re-launched for the media to be correctly recognized and accessed. DAE 5.1.1 CS 1 includes a fix that allows these types of media to be correctly recognized and accessed by Pro Tools when the application is already running. Please note that while Digidesign does not anticipate problems when using removable SCSI, "hot swappable"SCSI or Firewire drives with Pro Tools, these devices have not been fully qualified for use with Pro Tools at this time. For full details on qualified media for Pro Tools, please visit the compatibility section of Digidesign's web site at digidesign.com PCI Optimization for 33-64 Track Sessions with Pro Tools|24 MIX plus & MIX 3 Systems (Mac) Pro Tools|24 MIX plus & MIX 3 customers, (i.e. Pro Tools systems with at least one MIX Core and oneMIX Farm card) running large sessions, (33-64 tracks with high edit density, lots of automation data and/or large numbers of Plug-Ins), may experience "DAE 6042 - PCI Bus Too Slow"errors. These errors may occur due to the PCI bus being unable to handle the high volumes of "PCI traffic"required to play back the session. DAE 5.1.1 CS 1 improves Pro Tools PCI performance in these instances by placing the second 32-voice Playback Engine on the first MIX Farm card instead ofon the MIX Core card. Digidesign recommends that Pro Tools|24 MIX plus & MIX 3 customers regularly experiencing 6042 errors try this version of DAE, as it may reduce or prevent the occurrence of these errors with a particular session on a particular system, depending on the extent of PCI-bus overload.Who Should Use this Update?This update should be used only by:- Any Pro Tools TDM or LE 5.1.1 Macintosh user wishing to add removable SCSI, hot-swappable SCSI or Firewire media to their system, without needing to quit and re-launch Pro Tools for correct recognition and operation.- Pro Tools|24 MIX plus & MIX 3 system owners (i.e. with at least one MIX Core and one MIX Farm card) experiencing 6042 errors to alleviate the occurrence of this error.Please Note:- Pro Tools DAE CS 1 is provided is an interim "customer support (CS)"release to address the issues described. While our testing has not shown any problems to be caused by these changes, this version has not been fully qualified by Digidesign. For this reason, we recommend that you only install this version of DAE if you need the specific functionality it provides.