Strange php behaviour

At the weekend I upgraded my Gentoo system including php from 5.2.9-r2 to 5.2.10. It was one of the lot of upgrades. But the result was unique. The include_once php function was throwing error messages with this text: "Couldn't resolve hostname" and didn't include the file. I thought, I throw my hair because this is a very stupid error!

I searched on the Internet and I found this and this topic about this problem.

I have solved the problem because I downgraded php. I hope this problem will be solved soon.