possible fix to NO BANK INTERLEAVE (when 4 MODULES are installed): how to merge AWARD bios of similar motherboards

I own a legacy PT880 pro motherboard which make its good job for a common user pt88bspro-ec (jetway brand) it is good enough to support AGP P4 4 DDR400 DIMMs (3.25GB visible). Problem is the following:

2 modules installed Dual Channel = bank interleave working;
4 modules same RAM installed = bank interleave no -working although the option is enabled into bios.

I thought to use BIOSTAR PT880 PRO-A7 bios trying to merge bios in order to fix this problem besides having a better bios .

Is it possible to merge these 2 bios or to make BIOSTAR AWARD bios conform to Jetway model!?

@ Azrael5:
Welcome at Win-RAID Forum!

Although I am not an expert in this sort of BIOS modding, I do not recommend to try to solve your problem by merging different BIOSes. This procedure may brick your system completely.
Questions:
1. Are you sure, that all 4 memory sticks are from the same series and healthy?
2. Have you already tried alternative RAM combinations and to change the localisation of the individual RAM sticks?

Regards
Dieter (alias Fernando)

Thanks for reply.

Yes they are 4 ocz platinum ddr400 which have the same timings. If I uninstall 2 of them and then replacing the others I get bank interleave working on the 2 only slots occupied. So I assume BIOS disable bank interleave when 4 modules are installed because unknown reasons… perhaps because of AGP aperture size which shares memory… bios developers have not managed for my motherboard.

If it is not recommended to merge bioses is it possible to modify some hexadecimal to enable bank interleave for 4 modules!?

EDIT by Fernando: Unneeded parts of the fully quoted text removed (to save space within the thread)

It may be possible, but you have to find someone, who knows,
a) which BIOS module is responsable for the RAM interleaving feature and
b) which bytes have to be altered.