Question [Q] proximity sensor issue

hi.
i have a p500 and i am always changing roms and the last rom i have flashed recently is rc5 4.4 rom from jenkins. i don't remember but once i flashed a new rom a few month ago, i recognized that the proximity sensor does not work during calls. that means the screen does not go off in calls and my ear touches the screen and menus. so i searched a lot in internet and forums and found some solution for it but none of them fixed it. the last solution was in this link: http://forum.xda-developers.com/show....php?t=2353972 but the problem is that there is not such file sys/class/sensors... so what should i do? i have to mention that i have tested the proximity sensor with an app named androsensor and it shows that the proximity works well and detects my finger. so any suggestion or guide could be useful. please help me because this problem irritates me a lot.
phone: LG Optimus One p500
ROM: CM 11
Kernel: Stock kernel
Overclock: 320~729MHz - Smartass V2