Intelligent Systems recalled the IS-CGB-EMULATOR and IS-CGB-EMULATOR on 30 November 1998, due to an error when using address A000H of the DMG-MBC5-32M-FLASH or DMG-MBC5-32M-R-FLASH . Affected models had serial numbers between 98060001 and 98110568. The fix appeared to be a hardware modification, to be performed by Intelligent Systems.

Does anyone remember this? How can you tell whether a machine has been fixed or not? Does anyone have a "faulty" unit still?

You can find the info on the recall here:

It seems to be talking about reproducing the error using bank switching by selecting External ROM on the Emulation menu.... but my Japanese isn't too great!