I have an HP ML350 G5 server running MS SBS 2003 R2 SP2. I have installed a Tape backup solution consisting of an HP SC44Ge HBA w/ StorageWorks Ultra 448 SAS TBU. I am running Symantec Backup Exec version 12. When all were initially installed all was OK. But after a week (5 days) of normal operation we start getting Event Error ID 129 which is immediatly followed by and Event Error ID: 11. I have updated the HBA BIOS and firmware. I have replaced the HBA controller twice and the TBU one time. Every time I reinstall Back Exec or replace the hardware it seems to work for awhile and then the errors are reproduced.