so i borrowed this jazz bass from my friend (whose a guitar player) to "fix" it up... i restrung it, cleaned it and fixed the action..so i thought. what happens is everytime i adjust the trussrod and get the bridge to where its easy to play but doesnt buzz..the neck seems to warp over night (or within a few hours) and completely screws everything up! should i keep trying to reset it until it stays..or what should i do?! has anyone had this problem before?! thank you all for your help!