completely useless bug report follows, but I feel obligated to offer it.

4.1, dual mining in linux.  after several days,

read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable
read(): Resource temporarily unavailable

attempts to restart mining just hang.
soft (AHCI) reboot fixes it (implies not a hard hang at GPU/driver).