cutting issue

[livinloudgraphics 39]

hello i have a pcut and its the 24" i have been cutting for less than 1 months and it just started not cutting the whole letter number etc out it leaves a small little mark so when i weed it, it just pulls apart with the un-needed vinyl. ive tryed messing with the overcut and set it from 0.000in all the way to 0.100in changed the blade, made sure the vinyl wasnt moving. It done fine with the first set of graphics ive done, but now its just mind-bogging of what happened. when i do a overcut it cuts into the graphics it self, and when i dont add one it doesnt cut it out all the way. if i do a 0.050in it leaves little marks in the vinyl (slight cuts) and you can see them when you apply them. ive had some nice people up here on USCUTTER to help with this issue but they got mind bogged too when it didnt work out. so what else could it be?