Program fails crossing code page

[Art]

Hi Guys,
Is there any obvious reason why my PBP program
Does not work when it becomes large enough to
Extend to the third code page (16f877a) ?

No vars are accessed in asm other than in the ISR.

I can finish it in the current code space, but it would be nice to use it.
The program is working as expected until just one
Instruction crosses the third code page.
Cheers, Art.