DSR pin 6 and 22 on your DB25 pinout are shown in reverse polarity.
Here's your page that has the type-o..
http://pinouts.ru/data/cisco_530_pinout.shtml
Here's the correct pinout, (table B-3)
Checkout..
http://www.cisco.com/en/US/products/hw/video/ps1870/products_administration_guide_chapter09186a0080221af4.html#wp1005092