Yeah, I would like to see the full code too, with html, the post data which is sent and how it is gathered and etc. I think it is just a logical mistake somewhere in the code or just it is one of those things which you can't see even if it is so visible ;] I remember I spend some time on such stupid errors, but after a week I just checked with my clear head and found it very fast, in fact, it happened much more times than one

Agreeded. I've not been coding for long but sometimes do make such mistake that are so visible. And when I show my codes to someone else, they just find out the root cause within a few minutes. So if you want to share your codes, just paste it. Definitely someone will be able to spot something.