Display driver MAX7219 vs MAX6951 with 08M2


I would like to switch from MAX7219 to MAX6951 as a driver for a 7 segment display counter controlled by a 08M2. After reading the very good Ron Hackett book ("PicAxe microcontroller projects for the evil genius") , the Maxim's datasheet for both MAX7219, MAX6951 and the one explaining how to migrate from 7219 to 6951 (application note 876) , I get the following result :

1) A VSM simulation that works fine with 08M2 and Max7219 (cf attach files)
2) A VSM simulation that does not work with the Max6951 and I do not understand why :-(

I join to my post the VSM files and programs for both simulations
(In both case , I setup the SPI Debugger and I use a registered version of VSM picaxe 7.10 with latest patch 4.0.4 installed)

I will very much appreciate any comments on that matter