USB2.0 to slow

[Hellboy]

...im currently trying to safe data from my laptop on a usb harddrive using knoppix 3.9.
unfortanetly the transfer rate is extremly slow, although on starting it's much, much faster (by 10 to 20 times),
but after 10 - 10 seconds the transfer rate drops to about 1MB/s.
somwhere i found a notice saying that the "sync" option might be the problem, making file transfer safer but
also slower...
despite of that, i am just an average windows user, with not much of an idea how linux, knoppix really works...sorry!
anyway i would appreciate any help related to speeding up the transfer rate to reasonabel values.

best

jürn

[Hellboy]

...hm and it works fine with kanotix...