Well you are not 100% clear here, but if i were to make an educated guess -
You say you are not reaching the seam component. So i assume you have some sysouts in there and none are printing?
In that case you are probably dieing in the JSF lifecycle somewhere.
Check to make sure you aren't setting any objects awkwardly. Like you have an int field and typing a string into it. Since that will then cause it to fail.