Flickering with an Arduino1284p about arduino-tvout HOT 3 OPEN

A couple of notes i forgot: 

- My ATmega1284p is running at 16Mhz
- The output I attached is not from the DemoNTSC, is another example I created 
that draws a rectangle with a cross between its corners, you can see that the 
image is also drawn with a horizontal offset (thats the flickering).
- I had tired the example sketches and schematic with an Arduino Duemilanove 
(ATmega328p) with both version and it works fine

I have a atmega1284p as well and I also have troubles with it.  The issue 
varies depending on the resolution used. from unusable to almost non 
existent(120x96 works pretty well).

The issue is caused by the line handler taking to long on the 1284p vs other 
devices. It can be fixed by changing 
_NTSC_TIME_OUTPUT_START/_PAL_TIME_OUTPUT_START to a slightly higher value (15 
for NTSC and 15.5 for PAL seem to work perfectly although this may shift the 
image of the screen....)

Are you using the sanguino cores? I am wondering if there is an interrupt 
firing that cannot for this library to work. Although I have not heard of this 
issue effecting standard sanguinos.

Demo sketches work fine for me although maybe I have fixed them since the last 
push. Ill look into it.