Im having a bit of a problem here...

I have made a application that does some encryption on strings. all
encryption is done on the target machine except for the
license file encryption...

but heres my problem... on some machines i get an error message stating
"Cryptographic service provider (CSP) could not be found for this algorithm"
I have checked and triplechecked that i have the framework, and framework
SP1 on the target machine but it still produces this error...
i have also tryed it on one other Windows XP machine with the same
framework, and framework sp1 install files and there it works fine

I have the system.security.dll installed on the machine where its not
working and it works flawlessly on my development box...

Does anyone have any idea on what may cause this and how to fix it?

im using both 3DES and SHA512 all that should be part of the framework
right?