My Samsung Spica can't detect the SD card anymore

Recently I found a surprise on my Android notifications bar, telling me that the SD card is removed. I unplugged it and plugged it again but it didn't work. I rebooted the device; still not working. I tested it on my laptop, and in another device. The SD card is detected and it's working just fine. I tried my friend's SD card but it also couldn't be detected! By the way I bought this Spica last year and I never had an issue with the SD card before. Finally and desperately I formatted it to Ext2 format on my laptop, and it still doesn't work on the Spica. Any one have this issue before? How to deal with or how to fix it?