After a night of angry typing and googling to find a solution why my scripts that worked on PHP 4.2 and used NuSOAP now show the following error on PHP 5:
Fatal error: Cannot redeclare class soapclient in D:\www\nusoap.php on line 7240
The thing is that PHP5 has its own built in class soapclient and this is where the error comes from.
The solution to get NuSOAP working on PHP5 is quite simple. Open the nusoap.php file and replace soapclient with mysoapclient or whatever you think of. Use a mass find/replace if supported by your editor.