Memory stick troubles

Hey, everyone, a slight problem regarding a memory stick and the PS3. So, I have a 60 GB PS3 compatible with memory sticks (and with the three slots to the left of the disc drive) and a SanDisk Ultra Memory Stick PRO-HG Duo, and I would like to use it to store content for my PS3. Problem is, no matter how hard I try, I can't seem to be able to insert the stick into any of the drives. Do I have the wrong memory stick or is it just me sucking for not being able to insert the memory stick? And also, how would you then be able to put content on it? Thanks to all those that respond in some way :)