HELP!!, Usb Flash Memory Partition Problems

I just receive a u-stix 512mb flash drive, it brought some security and partition program, I decide to divide my F.D. into 2 halfs 256 each, one with password, the other normally. The problem is that now i can only access the unprotected part, the other one appear as a disk drive, and when i hit it it says insert disk, and the little program?, no where to be found. Please i really need help to undo these, or a program to merge the two partitions, help!!!