TFTP Transfers are slow to some machines.
You can download an up to date version of the startrom.0 file from http://support.microsoft.com/kb/906425 or obtain from Windows Server Support Pack 1 in the C:\Windows\ServicePackFiles\i386\STARTROM.n12 (rename to STARTROM.0).
Replace the existing STARTROM.0 in LANDesk\ManagementSuite\LANDesk\VBoot\ and redeploy any PXE Reps.
If a manual copy is desired, the STARTROM.0 can be replaced on the PXE
Representatives by overwriting STARTROM.0 located in \Program
Files\LANDesk\PXE\System\images\x86pc\undi\winpe, and \Program
Files\LANDesk\PXE\System\images\x86pc\undi\wpemenu (all WinPE options).
Get the core on a faster network, Add an IIS application Pool for the the Imaging Process. How big is your dosmeun.cfg file. I find it hard to believe it takes that long... Anyway First answer is most likely the best one.... Just throwing in my 2 cents worh... There is an IIS document attached, I am sure its on here already but I could not find it... ;p)