When formatting a compact flash card for use with an Eventide product you will want to do so in the FAT format not FAT32. Mac's aren't able to format in this type so you can use the Eclipse to format your card.
Insert the card into the Eclipse and press 'setup' until you see "utility" and select it. Then select 'format'. You'll be asked if you really want to format it and select yes. It will only take a moment to format the card and it will indicate when this is complete. Once this is complete remove the card, and insert it into your card reader/writer and transfer the files for the 3.51 software. Follow the instructions provided for this method and you should be set.
Please note it is best to use a card that is below 2G capacity. If you continue to experience an issue feel free to contact firstname.lastname@example.org for further assistance.