As of serial number 2585, Net3 RFRs will have an amber screen that does not support grayscale. This results in a "snowy" appearance on the screen when firmware earlier than 2.08 is loaded on them, as illustrated below.
The old RFR screen is part number M7283, and is green in color.
The new RFR screen is part number M7284, and is amber in color.
From an email from Kirk Starks earlier in 2011:
The solution for an RFR that has had version 2.07 (or previous) loaded onto it and is displaying this problem is to reload version 2.08.
Version 2.08 handheld is compatible with version 2.02-2.05 versions of base station