Working around Lock Screen problem when using SD as HDD

PC: Samsung Series 7 Slate (supplied with Windows 7 originally). Core i5, 64 GB SSD, 64 GB SD, 4 GB RAM. Now running Windows 8.1

I recently has a real problem with the configuration or ability to change the lock screen images. Now, much has been written about this and in my case, the cause was definitely because I used my 64 GB SD card as an additional disk. I had checked the option to save my documents, images and music to the new SD. I also went to Explorer and used the "move" feature on the Locations tab. I set the path to a new path I had created D:\Users\<me>\Documents etc... and opted to move the files when prompted. All lovely stuff. I did this for My Pictures, Downloads, My Music and My Videos.

It was only about 2 weeks later, that I found myself going to the settings area and found that if I clicked on Lock Screen, or the PC and Devices menu item, that the settings page just closed out. This is where I began to search around for some clues, and came across an item about the Lock Screen cache folders under:
C:\ProgramData\Microsoft\Windows\SystemData (Lockscreen_z etc).

I deleted all the images there (after taking ownership of the folders), and then found that I had access to the settings restored, but no image preview, and also no thumbnails of the 5 or so default images that usually span the main preview in a row beneath. Clicking on browse, took me to the My Pictures folder, but of course does not allow you to view the C:\Windows\Web\Screen folder where the default images are held. I was able to copy that folder as a test to the My Pictures folder (on SD card) and choose a lock screen image. I still found though that the 5 thumbnails still would not show.

In the end, I had to reset the default save location back to C:\ and then moved the My Pictures folder back to its original location. I left the other folder on the SD card though as it was very large and did not want that consuming space (my original reason for moving to the SD card). I was still having problems though and upon deleting the cache again, I found that I could not choose any images as a lock screen, and still no thumbnails.

Finally, I had to delete the test folder and re-copy it to the My Pictures folder (now back on C:\) and I got the lock screen image back. I had to go though each lock screen image to verify that I could change it, and upon choosing the tower image (img100.jpg) suddenly all the thumbnails reappeared and the whole Lock Screen settings were restored to normal.

So going forward, I have set up the SD card version of the My Pictures folder as a member of the Pictures Library, and also created a short-cut to the SD Card version in the My Pictures folder on C:\.

It seems somewhat odd that even when using UI provided functions, I obviously cannot store certain files where I want to, or on a piece of storage that has more available space?

Does anyone have any reliable means for safely moving large folders from system defined areas to the additional storage on a SD card? I want to resist doing any major registry hacks, but I would really like to move the SkyDrive folder on to the SD card too as it is getting pretty huge?