Well, first thing is first. When you said that you have above 3.55 OFW, are you talking about your on a firmware higher than 3.55 or your base firmware is higher than 3.55?
If you don't know your base firmware, use MinVerChk.PUP to check your base firmware. If your base firmware is 3.55 or lower, you can downgrade. If your base firmware is above 3.55, then you can't downgrade at all. If your ps3 is a 3k model (or over), it cannot be downgraded either.
I also don't believe the Matrix NAND programmer will work either. I recommend Progskeet or E3. You can have two different types of flash chips, a NAND and a NOR.
Please use the charts in the attachments to get your ps3's information.