HG is right. The R4 doesn't do HC. If they made a 32GB microSD that wasn't HC the R4 would probably work with it, but they don't. Once upon a time, for a brief shining Camelot-like moment, there were supposedly 4GB nonHC microSD's around. I never saw one and I never got one. Now all the 4GB cards are SDHC. If anybody every finds some Kingston or Sandisk 4GB microSD nonHC cards someplace, there is probably a small market of R4 owners that would snap them up. Anything that is 8GB is SDHC and won't work with an R4.
Yeah man, I heard about those too. Like you though, I've never seen one either. Otherwise I would've probably got one and packed it with vids.