[TYPO3-english] BE login does not work after update to php 5.2.9

[Vahan Amirbekyan]

I am running T3 4.2.6.
After upgrading PHP to 5.2.9 the BE login stopped working.
I tried clearing cookies, truncating be_sessions table. Nothing helps so 
far.

Also phpmyadmin v4.2.0 ext throws "You must set SignonURL!" error after 
the php upgrade.

any hint would be appreciated very much.

regard,