Hello,
 I am having some issues with a manhatten 28 USB port and these minors.  I will list my setup below.  Hopefully someone has a suggestion on fixing it.  Dualminer recognizes all of them,.  Everything runs fine when loading but then I get comm errors and it says failed to load dualminer on comm17.  It does this for all of them. I am connected to the pool as new blocks are found no mining happens.
Thank you

windows 7 home premium
Desktop
Manhattan 28 USB port