Slic 2.3 request fro Dell T7400

Hi there,

I've tried to add a SLIC 2.3 to the latest Dell T7400 BIOS but I keep getting an error. 
I'm using AndyP's Phoenixtool v2.66 and cert and bin from MDLs repository (linked below).
Always comes back with "Program Payload Error" when run from DOS.
File size after mod is always 5KB smaller..?

The A11 BIOS I am trying to modify already has a 2.1 SLIC in it.. I am using Dynamic method but with all default switches (too nervous to try advanced settings, although I've seen a few posts suggesting this may help)

Can someone help please?

Here are details:

Motherboard Manufacturer and Model : Dell T7400
-Bios Revision : A11
-Bios Type : Phoenix (Dell)
-Bios SLIC : Dell 2.3
-Bios Link : http://downloads.dell.com/FOLDER00493882...400A11.exe  (EXE version)
-Bios Link : http://downloads.dell.com/FOLDER00493883...400A11.bin  (BIN version)
-RW Report: https://www.sendspace.com/file/3r77pu
-Dell 2.3 SLIC and Cert I've tried: https://www.sendspace.com/file/fcq9i9

Many thanks for any help!!!!!

Will