Below is the source I'm using to control my path settings.  I just downloaded and updated with the 5.1 version of CE.  My images work fine.  My media gallery and image gallery folder is registering fine.  Any ideas?

    If Not Page.IsPostBack Then
        Editor1.SecurityPolicyFile  = "guest.config"
        Editor1.Setting("security:ImageGalleryPath")= "~/blog/images"
        Editor1.Setting("security:MediaGalleryPath")= "~/blog/images"
        Editor1.Setting("security:FlashGalleryPath")= "~/blog/images"
        Editor1.Setting("security:FilesGallaryPath")= "~/blog/images"
        Editor1.ShowDecreaseButton = False
        Editor1.ShowEnlargeButton = False
    End If

I found the problem!  I cute and pasted some code Cute Soft's example pages.  A varible is spelled wrong(FileGallaryPath instead of FileGalleryPath) on them so they don't work right.  Here are the pages I found (via Google) that has the misspelling:

 

 

The misspelling has several reposting in the forums as well:

Thanks for pointing out the error in the developer's guide.

We will fix it as soon as possible.