immigration

I am a green card holder and came here 29 july 2004.i have spent 4 months out of states since i am green card holder.for some reasons i m having difficulties in continuing my residence here.i want to go back in dec 2008.my question is "is that possible that i apply for my naturilization in dec.and do my finger prints and take a re-entry permit for a year and leave tha states for a year and come back when i'll receive the letter for my interview".cause if i'll leave in dec only 6 months will be remaining in completion of my 5 yrs of permanant residence.will that 6 months will delay my naturilization process??

or tell my any solution so i can live outside states as much as possible without delaying my naturilization because at the time of leaving in dec i'll be done by four and a half year of my continous residence and i dont want to losse it.