Errors with Soft RAID 5 Array, no disks off line

[vamythguy <vamythguy@xxxxxxxxx>]

I have a 4 disk soft RAID-5 array and I'm receiving a ton of these messages in the system logs:

Dec 31 17:04:38 tibeaux smartd[2384]: Device: /dev/sda, 3 Offline uncorrectable sectors
Dec 31 17:04:39 tibeaux smartd[2384]: Device: /dev/sdd, 48 Currently unreadable (pending) sectors

But cat /proc/mdstat reports:

Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sda[0] sdd[3] sdc[2] sdb[1]
      735351936 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]

unused devices: <none>

Best way to fix this, or is it not a problem?