Originally Posted by Orochi
I haven't loaded very many books onto the SDHC card yet, but if I go into the Settings Overview on the Reader itself - it does recognize all 4gb (or close to it anyways) under the Removable Storage heading.
I'm just going from what's happened with other readers in the past which have had hardware SDHC support, but no firmware support - eg the Sony PRS-505. With those, all 4GB show up in the card capacity, but content beyond the 2GB point can't be read. The Sony subsequently had a firmware update which added SDHC support, and then high-capacity cards worked fine.