It's just a general problem in my area during nights (after 8-9) (bellrose.. queens, ny). My transfer rate will be okay now since it's 5:50pm. It's been this way for months.
I saw this thread and realized there are many people in the same boat as me that live in queens. Supposedly the 3-5 months of slowness during nights is due to upgrades. Someone said it should be better by the end of summer but we'll have to see.
http://www.dslreports.com/forum/remark,16561694~days=9999