Crunchy Sound

[ostaryus1]

My laptop has conexant hd 221 sondcard. I installed Kalyway 10.5.2 and it works great except wifi. My problem began after installing updates. After updating to 10.5.4 my soundcard started to work problematically. It sounds crunchy like a disturtion. Especially while playing videos sound is cutting for about every 3 seconds. I did not understand the problem. But I discovered that when I write "update" or "update -v" on the boot screen, It works normally. Is there anybody gets the same problem and do you have any solution. I tried almost every kext file but the issue still continues.