Memory Reallocation

[Gamo]

Recently I program the Matrix of 3x3 to solve for
Three Equation in Three Unknowns on
HP-12C Platinum that took 13 Store Registers with
155 program steps. Test it and program run flawlessly.
So I try this exact same program in HP-15C but
Not work as expected the register used R1 to R.4
Same as on the 12C Platinum.
When input each element it struck at STO 8 and
Shown error 3

I'm wondering why it doesn't work on 15C that
The program capacity is 400+
Is this have to do with the Memory Reallocation might work different than the 12C Platinum.

Here is the link to 12C Platinum program.
http://www.hpmuseum.org/forum/thread-11909.html

Gamo