It sounds like you've got a failing drive. The MediaSmart Server is fickle when a drive is on its way out. It's perfectly possible for a disk to be failing but it'll come back "clean" when a CHKDSK is run on a different PC. A failing disk isn't always going to be detected by CHKDSK, which checks the file system integrity and can optionally scan for bad sectors. Bad sectors are not always the demise of a disk. Other errors -- end-to-end errors are a big one; end-to-end errors mean there is corruption between the disk's onboard cache and the actual reading from or writing to the disk. Spin-up errors, raw read errors, ECC failures, etc. are all failure indicators and there is no guarantee CHKDSK will detect them.
My first inclination would be to tell you to install Home Server SMART. There are two versions of HSS -- Classic and 2015; the former is for WHS v1 and the latter is for WHS 2011, 2012 Essentials and 2012 R2 Essentials. Both are very recently updated, and both are freeware. Visit
http://www.dojonorthsoftware.net/HomeSe ... assic.html or
http://www.dojonorthsoftware.net/HomeServerSMART.html to get Classic or 2015, respectively.
Now since it sounds like inserting the data disks in your server causes the server to lock up, getting Home Server SMART installed to check the disk health may not be an option. Fortunately, you can install WindowSMART 2015 on the machine you used to scan the data drives. WindowSMART 2015 is shareware, but runs for a full 30 days without limitation. Install WindowSMART, insert the disks and then make sure WindowSMART has plenty of time to conduct an initial polling of the disk. It can take 10-15 minutes before data appears, or you can go into the Settings (from the Edit menu), go to Service Control and click Restart Service. Restarting the WindowSMART service will cause an immediate polling. Do that, wait a minute, then click the Refresh button in the UI, and you should see the disk results. WindowSMART is available here:
http://dojonorthsoftware.net/WindowSMART.htmlWhichever tool you use, please take a screen grab and post your results here.