Ok, Erik.
I have another problem with the Prescaler number

On page 109 of UM says that the reset value for WDCON is 111xx1?1B, which means that my prescaler value is a litle more than 174.8 ms using the PLCK at 7.373 Mhz.
But when I run the program the WDT always generates an interrupt and the time out period is 32, which means the prescaler is 000 instead of 111 (page 110). I forced to 111 by setting WDCON |=0xE4;, but still looks like 000 and generates an interrupt.
Any ideas here?