FreeNAS iSCSI disconnecting

Hi,

I have a FreeNAS 0.69 Kwisatz Haderach (revision 4276) box with 2G Ram, and 1 x 80G(the OS is installed here) and 2 x 1TB (setup in a Raid0).

I have this hooked up to a windows 2003 server and am doing disk to disk backups, but everytime during the backup it disconnects and if I look at the FreeNAS logs it all gives me this:

iscsi-target: pid 2359:util.c:894: ***ERROR*** readv() failed: rc -1 errno 60
iscsi-target: pid :target.c:: ***ERROR*** cmd.tsih 0 not found

I found some stuff on the net where they say it is the iscsi crashing and i should try increasing the follow:
vm.kmem_size and vm.kmem_size_max
but now if I try :
sysctl vm.kmem_size="1610612736"
sysctl vm.kmem_size_max="1610612736"
I get an error saying:
sysctl: oid 'vm.kmem_size' is read only


Please Help......


Please help...