Partition disappeared (different to some

I have a 10 Gb drive and a 4Gb drive. The 4Gb is partitioned into 2 2Gb bits. Recently, I have had problems with installing new memory, and have had to go back from 160Mb to 64Mb. The second partition on the 4Gb drive has since disappeared. Any ideas?
Fdisk shows that it’s a 2 Gb drive at 100% usage with only 1 partition.

REALLY need help on this asap.