What website are u testing the speed at? Try going http://myspeed.visualware.com alot of speedtests on the internet are not able to accurately test upload speeds over 10meg. Also make sure if you have any internet security programs (norton 360, Verizon Internet Secuirty Suite aka VISS, etc) firewall turned off. Are u testing this on a wireless connection.. Wireless connections are not always as fast as wired connections due to signal loss.
I was testing using www.speedtest.net. I'll try the site you mentioned, but the person that did my installation recommended this site.
I also need to mention that verizon upgraded my service from 15/15 to 20/20. Prior to the upgrade, I was actually getting 15.5/13.2 from the test on SpeedTest.net. With the upgraded 20/20 speed, I'm only getting 20.7/9.8.
I had this problem and what I did to fix it was to shut off the router and reboot the ONT by unplugging it and remove the battery for about 10 Mins.
Then I re-powered the ONT and turned the router back on. Before I did this I was getting 20 / 10-11 after its been 20/19 going the non-verizon
speed test sites.