You don't specify the units of all of the download/upload measurements above - are they KBps (kilobytes per second i.e. units of 1024 bytes per second)? For a broadband connection of [broken link removed] (presumably nominal rating of 512Kbps download/256 Kbps upload where Kbps is kilobits per second) a download speed of c. 40-50KB would be more reasonable. Of course it also depends on the contention ratio for your line (i.e. the number of users sharing the one "pipe").