Hi Adam,
Had a quick look at the scenarios and here's what we have:
* When you have the Template dialog box up, and you pick a htm from the file system, it is uploaded correctly (meaning it is prepended with the security prefix (SOME_PREFIX_) and it shows up in the file picker.
* Things are a little more erratic on the Template Creation feature side. If you use the Create Template button in the said Template pop-up box, you will be offered a pop-up to take your file name. If you were to type in a regular file name. (blah.htm or blah) it will create blah.htm, but it will not show up in the dialog box. (So the problem, we are guessing is: the component is not renaming it but still applying the security view to the file picker, causing "files to disappear").
* If you were to explicitly prepend by hand (SOME_PREFIX_) the security prefix to the file name during template creation, it's all good. It shows up as is.
* Again, as pointed out before, Images are working fine. [Note: we haven't tested for this SetSecurityFileNamePrefix() bug with other upload types such as Files/Documents, Flash, and so on.]
Please let us know if there's something you can do to mend the SetSecurityFileNamePrefix() bug, thank you! :-)
All the best,
-- David