Hehe no clue to be honnest.
I picked up a PSP 300x with GEN-A pre installed for 70 euro yesterday night.
It also had Skype pre installed onto it as my mate who did own it used to skype with it.
So let us hear or AndreXL his suggestion did work.
Id like to know or this still works if your run a FW lower than required to enter the PS Store.
Greetz, Vistabuser.