I am restricting the size of image files my users are authorized to upload with the following C# code:

cm_htmlcontent.SetSecurityMaxImageFolderSize(1024 * 5);
cm_htmlcontent.SetSecurityMaxImageSize(150);

When I upload very small images (30KB or less) it works fine. However, when I attempt to upload a file that is a littel bit larger while still being under the max size I get the following error message:

 

Why is CuteEditor refusing to allow a file that is clearly smaller than the maximum allowed?