Interestingly I bought my I2 and PH4P to a gig after a new firmware update for them both. Oddly I have now been getting the Slow card warning of both machines using the same cards I have used for months (and btw the cards that came with the units)
I did a reformat in the air and it changed nothing (although it then only seemed to happen when I was shooting in clog) I did another reformat on the ground and so far so good on the I2. I have not yet checked the P4P