Mine 8mb down, 0.4 up, tested sucusss with a wired connection.
They need to be more specific on error message, give us better knowledge on why we fail.
Unless you are using different numbers, .4 and .6 as upload...? thats ridiculously low,unless you guys mean 6 Mbps and up...if its .6 Mbps,no wonder it doesnt work.
do the test here:
http://www.speakeasy.net/speedtest/