You can try using the nusoap library from moodle 1.6.
1. From moodle 1.6, copy moodle/lib/soap/nusoap.php to your moodle 1.5 directory moodle/lib/nusoap/nusoap.php (rename the existing nusoap library in there first).
2. Then in moodle/mod/lams/lib.php, do a search for 'soapclient' and change the text to insert an underscore, as 'soap_client'.
When you reach the 'create a lams activity' screen, can you click 'create new sequence' and get the LAMS author window? Doing this doesn't rely on soap.
Not sure why you get a blank screen instead of the normal 'tables have been created successfully' message.
Posted by Jun-Dir Liew