my phone isn't recognizing my larger 8gb sd card but it recognizes the 2gb card perfectly fine. When I removed all paritions from it on easeus it gets recognized but android can't format it. This card is recognized in windoze perfectly fine as well.
Use your favorite disk management tool to reformat the card to FAT32 and insert it in the phone. If I recall properly from the last time I did this, after the phone formats the card to it's liking, you can then copy any directories/files over from the 2Gb card.
If you don't have a disk management tool, try GParted live. It's free and you don't even need to install it on your machine.
Do you have the Gingerbread (ZVH) update? Huge flaw with it not recognizing, or recognizing and later unexpectedly removing, card. Instead of rolling back to ZVC I got a higher class 32gb and it works perfectly. I know they are pricey but there always seems to be a sale somewhere for ~ $30.
Any possibility your new 8gb is defective?
You have the zvh bugs just as this guy said