Using the COM functionality in PHP 4.0 beta 3 on Windows NT with IIS, I created a COM object and called a property that takes a parameter and PHP returns an error:

<?php
$obj = new COM("MyProgid")
$ver = $obj->Version("HTML");
?>

Fatal error: version.() in D:\php_scripts\com.php on line 3

Here is the COM propert get IDL:

[id(0x00000001), propget, helpstring("property Version")]
BSTR Version([in, optional] VARIANT format);

I took a quick look at COM.c and noticed that propget implementation does not appear to take arguments:

From COM.c:

do_COM_propget(...) {
...
dispparams.cArgs = 0;
dispparams.cNamedArgs = 0;

hr = i_dispatch->lpVtbl->Invoke(i_dispatch, dispid, &IID_NULL,LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &dispparams, var_result, NULL, 0);
...
}