Extended Error Handling (EEH) device drivers that allow recovery from intermittent PCI bus errors. This approach works by recovering and resetting the adapter, thereby initiating system recovery for a permanent PCI bus error. Rather than failing immediately, the faulty device is “frozen” and restarted, preventing a machine check. POWER6 technology extends this capability to PCIe bus errors.

If this is happening a lot I would rais an IBM support call