OK, have you logged in to your modem to make sure that you actually have the 10mb config file?
(assuming you have an ambit modem)
to do this type -
http://192.168.100.1/ in to your web address field
the username and password is root
click on Operation Configuration and check that your -
Maximum Downstream Data Rate : 10240000 bps
Maximum Upstream Data Rate : 512000 bps
is as above.
If not, then you do not have 10mb.
Keep us posted....
hth