Aredwood: Check your PPP username. If it is simply "username" instead of email@example.com speed profile changes don't apply properly. I found this out the hard way when I moved from 100/50 to 200/200 I ended up with 100/200
This issue of profile not being applied properly seems to have hung around since forever. I experienced it myself when changing from 30/10 to 100/50 a couple of years ago. I wonder how many customers are impacted and don't even realise.