File permissions set at 644 - problem for vqmod?

I had trouble uploading vQmod & my hosting company wrote my index file must remain as 644.

Might that cause a problem running vQmod?

------- hosting company email start
I have only uploaded the 'vqmod' folder in to the root of your OpenCart directory and accessed the URL http://cricketcap.co.uk/vqmod/install but at that time I got an error message says that "Administrator index.php not writeable". The index file must remain as 644. Any other setting will not work on our servers. So I have commented out the below lines in the index.php file and the URL http://cricketcap.co.uk/vqmod/install/ loading fine with a message says that "VQMOD ALREADY INSTALLED!".

=====================
if(!$opencart_path) die('COULD NOT DETERMINE CORRECT FILE PATH');

$write_errors = array();
if(!is_writeable($opencart_path . 'index.php')) {
$write_errors[] = 'index.php not writeable';
}
if(!is_writeable($opencart_path . $admin . '/index.php')) {
$write_errors[] = 'Administrator index.php not writeable';
}
=====================

You have to update the index.php files to work the VQmod properly.

------- hosting company email end

Generally all files should be 0644.
In rare cases (depends on your provider) it could be also 0640, 0600 or 0666

Directories should have always 0755
Same here, sometimes 0750, 0700 or 0777

Sometimes if have troubles to access a file, check also the folder permissions, not only the file permissions.
Both have to be set correct.