found the problem, it was the watchdog but now i can get the interupt to trigger properly.
it seems like once the interrupt is triggered it just keeps triggering? even if I strap it to ground while running? strange

Code:
on interrupt goto firetriac
intcon = %10010000
scan:
fire = 0
if up = 1 then 
delay = delay + 100
if delay > maxdelay then
delay = maxdelay 
endif
lcdout 254,1, dec delay
endif

if down = 1 then 
delay = delay - 100
if delay < 100 then
delay = 100 
endif
lcdout 254,1, dec delay
endif
 
goto scan


disable
firetriac:
pauseus maxdelay - delay
fire = 1
pauseus 10
fire = 0
intcon.0 = 0
resume
enable