"New Folder" Missing But Only In Certain Places?

I've come accross an unusual problem that I've never seen before.'m on windows 7 home premium 64 bit.I have a Library called "work". Its actually located in my documents folder.In this folder I have WorkDiscsubuntu. As you may have guessed I work with linux on occasion.I wanted to create a new folder here but the new folder button was missing from the toolbar and the context menu.I can create a new folders elsewhere just not here.I thought as an easy workround I would create a new folder in the parent directory and simply move it. I created it in workdiscs and then moved it into "ununtu" only to find it wasnt there.If I navigate to the real location of this folder the new folder is there ok.

Then I thought if this folder is playing up I will create a new one and just delete this one so I created workdiscsubuntu2 and moved all of the contents of ubuntu to here.So far so good.I then created 3 new folders here "1004" "1010" and "1104" I then moved all the files from ubuntu into these folders.To be clear now workdiscubuntu2 should now contain 3 folders and no files.I then deleted ubuntu and renamed ubuntu2 --> ubuntu.I then double clicked on the new "ubuntu " folder expecting to see 3 folders yet I see the contents as it was before I started. If I call it anything other than ubuntu I see the contents fine but if I name it ubuntu it reverts to its old state.