Cann't save excel 2007 document with PHPExcel 1.8.0 at the combat host



By means of PHPExcel 1.8.0 I've developed the php code, which generates an excel file. This code works well at the localhost server but at the combat host it doesn't work. As I found out the reason is in this one line of code:
$writer = PHPExcel_IOFactory::createWriter($excel, 'Excel2007');
If I change 'Excel2007' with 'Excel5' everything works. Some men tells that the reason is in the host settings. I'm using the selfmanaged VPS.

Please help me to understand the reason why do the excel 2007 document cann't be created at the combat host.