Hi guys, the Epson R300 does not support SDHC memory cards, only the standard SD format (and also Compact Flash Type I and II, MultiMediaCard, Microdrive, xD-Picture Card, Memory Stick, Memory Stick PRO, Memory Stick Duo, MagicGate Memory Stick, SmartMedia, Secure Digital and MiniSD).
SD cards range from the lowest capacities up to 4GB and SDHC (High Capacity) memory cards conform to a newer standard and are not available in less than 2GB capacity. SDXC is the latest standard by the SD Card Association that implements 64GB in SD format!
Techwhore28: The only thing I can suggest is that your 4GB SDHC is faulty.