Strange behaviour from PIC16F877 on TMR0

[mikebar]

Woohaa i try to figure out but there's too much 'maybe this or that' in my mind.
Can you post your whole code and schematic?

Thank you, mister_e.
Tonight I've found that absolutely there is not the software that cause this so strange behaviour. Since the board is under control of another one that drive 2 bigger motors in PWM (24Vdc, anytime separated from the power of the logic but this 24Vdc are the same that power the tiny motors where I loose pulses), I've found the following:
If I let one of this bigger motor to use a little bit more power (just because I'm trying to move the shaft with my hand and the PID controllers try to oppose to my strenght) THEN the strange behaviour start happening. If I turn off one of these motors, the "strangeness" do not happen.
Seems that there is some kind of disturbance that is picked-up by the micro.
I've putted so many caps and grounded any unused pin as you can see... what can I do more?
Also, when I start missing pulses on TMR0 (RA4) seems that I pick-up many other "ghost" pulses on RB0...

Thank you for your time.