invalid keystore format

Hello,

I have secured my application (client - server) with ssl.
That works fine.

Now I want to use the same application on PDA.
But when he has to load the keyStores with (the same) keys he gives an
invalid keystore format exception.
In both application he get an instance of the default type (= JKS).

I suppose there is a problem with the keys under different versions of java?
Does anybody know more?

TIA