Is it possible for a R360 core to run properly with an R350 BIOS? it stands to reason that if it's not, then ATI Tool can identify the core. Most software probably (drivers definately) uses the HID 4E48 to identify a Radeon 9800 Pro and 4E4A to identify a Radeon 9800 XT and simply presume they have the R350 and R360 cores respectively, regardless of BIOS information. Although, this is all presumption since the only pre XT 9800 I've had the chance to pop the hood on had a 350, as correctly and logically detected by ATI Tool. One thing I did notice was if you did flash a BIOS that didn't match the card's HID, they became extremely slow displaying IBM or line based resolutions. Although this is not directly linked to the core revision, it does show that the wrong BIOS does cause problems.