I experimented with changing SIS962L to sis961. Chips

I experimented with changing SIS962L to sis961. Chips are pin to pin same. When I soldered SIS961 to ASUS P4S533-MX, mobo started and post codes runing normaly. But, when it showes picture on monitor and showes CPU ID it stops responding.
Do I have to redact some BIOS elements? In POST I see that it still recognises SiS 962 that is not present anymore.

SIS 961/962/962Lua