Other than setting the 'BlockSize' in your constructor to something other than 10240 (I would start going smaller in 2048 increments then try larger than 10240 by 2048) - you might want to set 'Debug' and check out what is going on in the background.

Unfortunately that is not a lot of info to get good idea of what is going on

grep

Just me, the boy and these two monks, no questions asked.