SST49LF020/49LF002A - in than difference?

Recommended by Wim's BIOS...

MB Asus A7V266-E and Abit NV7-133R use SST49LF020. I have only SST49LF002A - on features much like it. But when SST49LF002A (with correct flashing) installing in the said belongings - get 00 on POST-card. But in an effort flash SST49LF020 on any other MB - get "unknown flash type". Why? That for the PRINCIPLE difference?
And else. Uniflash correct defines this type in Asus A7V266-E, but can not correct to flash. Aflahsh/Pflash do not know such tips, other flashers under DOS did not find - can prompt?

[Rainbow]

49LF020 has LPC interface while 49LF002(A) has FWH (Firmware Hub) interface. They're not compatible.

I seemed that this one and same. Thank you, shall to know. Then has stayed the second part of the question. Uniflash incorrect flashing SST49LF020 (in process appear uncorrect-flashing blocks) on MB Asus A7V266-E, while standard flasher from Asus this does correct (this flash). This because of Asus particularities?

[edwin]

Guess what...