TYPO3 Core

I've written an extension that requires EXT:vhs. So in my ext_emconf.php I put this:

    'constraints' => array(
        'depends' => array(
            'php' => '5.3.7',
            'typo3' => '6.2.4-6.2.999',
            'cms' => '',
            'fluidcontent' => '4.0.0',
            'vhs' => '1.9.1',
            'flux' => '7.0.0',
        ),
        'conflicts' => array(
        ),
        'suggests' => array(
        ),
    ),

When trying to install my extension, I get this message:

    Required extension "vhs":
        * The extension vhs is needed in version 1.9.1 - , but could not be fetched from TER

The problem is, that EXT:vhs is already installed and running, and its version is 1.9.1.

I could work around the problem in two ways:

1. Remove the version from the vhs dependency, so it ready 'vhs' => ''
2. Uninstall vhs, but not delete it. Haven't tried to delete it.

Happens in TYPO3 6.2.4, with PHP 5.3.27.