Having EX1 = 1; and its pin high
I assume you mean the interrupt pin. "YES"

Do you have an ISR for EI1? "YES"

Here is:

void Interrupt (void) interrupt 0
{
EX0 = 0;
// Do some stuff...takes (msec)
while (interrupt_pin == 0);
delay(10000); // glitch reject
// do some stuff... (takes msec)
EX0 = 1; // after setting it, wdt triggers causing an int.
return;
}