I encountered the erase phase immediately after the data download initial phase; several times, the Data Error occurred immediately thereafter. BTW, the uninstall you referred to is correct; HOWEVER, the 990 remained at that point in an unusable state...even after resetting the switch from service to normal, and trying unsuccessfully to do a system reset.

The software uninstall is just that; it has no effect on the potential lockup of the 990. Fortunately, the latter is apparantly correctable, with a successful DL of the firmware.