If you're using DEC in HSERIN, you want to use DEC in HSEROUT as well. You USART settings seems weird to me, this following..
Code:
DECLARE HSERIAL_TXSTA = %00100010
But HSEROUT should take care of it. You could still try...
Code:
HSERIAL_RCSTA=$90
HSERIAL_TXSTA=$20
HSERIAL_SPBRG=25 ' 2400 Bauds
HSERIAL_CLEAR=ON
This set manually the PIC USART register.

Proton forum