PHP 4.3.4 and Sessions

Hello everyone I have some major problems with the 4.3.4 version under Windows XP SP 1 with both, Apache 1.3.29 and IIS. PHP creates wrong(?) session files, it adds lots of spaces and a session file looks like:

status|s:2:"ok ";user|s:5:"admin     ";userid|i:14;language|s:2:"de ";
	      ^                 ^^^^^				   ^

I register the session variables with $_SESSION['status'] = "ok"; or it adds a space after a string which is very annoying at the Password verification, I just can't login to my application which *works* with versions < 4.3.4 :( Had someone a similar problem and has a fix for it?