Finally got a resolution from Symantec Support
They provided an 3 updated SBS files (SBSInterface.dll, SbsMtftp.exe,SbsServer.exe). - Version 12.0.0.7061
1. Next we needed to stop the services on the site server Symantec Network Boot Service (PXE and BSDP) & (TFTP)
2. Delete the Symantec Network Boot Service for PXE and BSDP - Open up CMD Prompt Elevated (SC Delete SymantecNetworkBootServicePXE
3. Copy the 3 updated SBS files to the SBS folder (Program Files\altiris agent\agents\deployment\sbs)
4. Create the service for the Symantec Network Boot Service (PXE and BSDP) - Open up CMD Prompt Eleveated (SC create SymantecNetworkBootServicePXE binPath= "C:\program files\Altiris agent\Agents\Deployment\SBS\SbsServer.exe" Displayname= "Symantec Network Boot Service (PXE and BSDP"
5. Start the Symantec Network Boot Services both PXE and TFTP
6. Recreate the Boot Environment