diff --git a/software/SCSI2SD/src/main.c b/software/SCSI2SD/src/main.c
index 114e8fb..aa144bd 100755
--- a/software/SCSI2SD/src/main.c
+++ b/software/SCSI2SD/src/main.c
@@ -94,7 +94,7 @@ int main()
 				CyExitCriticalSection(interruptState);
 			}
 		}
-		else if (scsiDev.phase >= 0)
+		else if ((scsiDev.phase >= 0) && (blockDev.state & DISK_PRESENT))
 		{
 			// don't waste time scanning SD cards while we're doing disk IO
 			lastSDPoll = getTime_ms();