PSP Not Reading Memory Stick's Help!

yea i have a problem with my psp, when i insert my memory sticks the psp blinks orange like its loading something, but it keeps blinking, then when i insertthe stick with a little pressure it loads but it either says i have 0kb or it shows i have space but when i click on something it says there are no files.

any ideas what could be wrong? i tried cleaning it but i think i may need to open it.

thanks