Hello,
 
Ii just purchased a new Q6700 to upgrade my E6600. I own a P5B Deluxe mobo with the 604 BIOS. Here's what I plan on doing to upgrade my cpu, please correct me if I planned something wrong.
 
1: (already done) Download latest (non-beta) 1226 BIOS, unzip it and put it on a USB key (FAT32 formatted)
 
2: Start PC going into BIOS, write down all the setting I used, and load default setting, thus putting my 3,0GHz E6600 back to 2.4GHz. Save and restart.
 
3: Go into BIOS again at restart and select (forgot name) to fing my USB key and proceed with BIOS update, after selecting my P5BD1226.ROM file. Reload after it finish.
 
4: Go into Vista to make sure everything works OK and shut down PC after.
 
5: Remove Big Typhoon fan, remove CPU, put in new cpu (Q6700), put a line of Arctic Silver5 thermal paste, put back Big Typhoon checking that the thermal compound is well distributed.  
 
6: Start PC going into BIOS and check that the CPU isn't overheating. Put up old setting, except CPU overclock. Save and restart.
 
7: After assuring that everything works OK, do my testing at 3.33GHz that I plan on using my Q6700.
 
I put up everything as well as I could think about it. If you think I forgot anything, please let me know. I really wouldn't like break anything or do it in more steop then necessary.
 
Thanks in advance. I'll come back this afternoon to check.

OK, 4 hours old (or so), 29 reads and no answers. I'll take that for a "everything I planned is OK".  I'll come back later to check again, I should be upgrading tonight.
 
Thanks again.

This might be a good howto for CPU upgrades/BIOS updates.
Just add "clean old paste from cooler" to step 5.

Between now and #3, prepare a bootable floppy or some other means of starting your system in case it fubars.  Put a copy of your current BIOS, and any necessary flash utility on the same media (e.g. floppy) in case you need to restore it.
Between step 3 & 4, reset the new CMOS to defaults.
At #5, clean off the old thermal paste (91% isopropyll alcohol works well).  When you put on the new paste, rather than a "line," use a rice-grain sized dot.  You can also smear it around with your finger in a plastic bag.

Thanks guys! Luckily I didn't have time to upgrade yesterday night. I'll make sure to do as you said.
 
Thanks again!

I think the ASUS P5B has a rescue method for bad flashes where you put your driver CD in and it restores the BIOS.
The general opinion is it sucks but sometimes it works. I've never had BIOS flash issues myself so I don't know.