diff -up ./src/coolkey/slot.cpp.max-cpu-bug ./src/coolkey/slot.cpp
--- ./src/coolkey/slot.cpp.max-cpu-bug	2016-06-30 14:36:10.502785885 -0700
+++ ./src/coolkey/slot.cpp	2016-06-30 14:36:15.812876256 -0700
@@ -1875,6 +1875,8 @@ SlotList::waitForSlotEvent(CK_FLAGS flag
 	if (status != CKYSUCCESS) {
 	    if ((CKYCardContext_GetLastError(context) ==
 						 SCARD_E_READER_UNAVAILABLE) ||
+	       (CKYCardContext_GetLastError(context) ==
+						 SCARD_E_UNKNOWN_READER) ||
 	       (CKYCardContext_GetLastError(context) == SCARD_E_TIMEOUT)) {
 		OSSleep(timeout*PKCS11_CARD_ERROR_LATENCY);
 	    }