[TYPO3-mvc] ext_autoload.php requirements?

[Thomas Mammitzsch]

Hi list,

are there some special features PHP needs compiled in or loaded as 
module in order to use 
Tx_Extbase_Utility_Extension->createAutoloadRegistryForExtension()?
I tried to create an ext_autoload.php via

$extutil = new Tx_Extbase_Utility_Extension;
$extutil->createAutoloadRegistryForExtension('myext', 
t3lib_extMgm::extPath('myext'));

but my ext_autoload.php just looks like that after creation:

// DO NOT CHANGE THIS FILE! It is automatically generated by 
Tx_Extbase_Utility_Extension::createAutoloadRegistryForExtension.
// This file was generated on 2010-10-13 12:27

$extensionClassesPath = t3lib_extMgm::extPath('myext') . 'Classes/';
return array(
);

The myext extension itself was created with extbase_kickstarter (latest 
trunk), so i guess i match the possible naming conventions.
i also tried to recreate the ext_autoload.php for an extension 
(extbase_webservices) by uncommenting hte extutil lines in 
ext_localconf.php for testing (while this file already has an working 
array) - same result, empty array on my machine.

regards, Thomas