I have been working previously with Web Services on Adobe forms (in SAP environment) with no problems.
I am currently working on prototype of Adobe Interactive Form using PHP (ver 5.3) Web Service(s).
However I am not able to make PHP Web Service work on Adobe form.
I have tested sample PHP Web Service using PHP script (SOAP client) and it works perfectly fine.
I have found somewhere information which suggests that I need to extend PDF with Reader Extensions which I did (using trial version of Acrobat Reader Pro).
Unfortunately it still does not work (not sure if call is being send at all when I press button which is supposed to trigger WS).
Please find below link to zip file including following resources:
IncreasePeriod.pdf (PDF file with implemented WS, w/o Reader Extensions)
IncreasePeriod_RE.pdf (PDF file with implemented WS, with Reader Extensions)
IncreasePeriod.wsdl (Web Service definition)
soap-server.php (PHP Web Service definition, SOAP server)
soap-client.php (PHP Web Service call, SOAP client)
Let me know if I did not make myself clear.
AFAIK Acrobat Extended features does not include the "invoke webservices" extension. for that you really need LC: Reader Extensions.
You could D/L a trial version and email adobe support for a RE certificate (its required in order for RE to work).
I don't see any workaround for this.