I've uploaded some very simple test recordings re the issues with the R-44 & the R-26 picking up the display panel noise - including two with the DPA's that also show some of the other issues related to those specific mics.
It seems to me that any recorder that picked up this level of electronic debris needs to be looked at seriously in terms of design. Most entry or pro-sumer level recorders will pick up a bit but these examples seem to be way above what's acceptable.
http://soundcloud.com/jrf-tests/sets/roland-r-44-r-26-issues