Why won't SWFUpload execute the upload.aspx code, and why is it saving all files to the root directory?

Question

I am using SWFUpload v2.2.
In IE (8):
  If I upload a very tiny file (16kb):
     1) The file appears in the root directory where upload.aspx is located.
     2) Page_Load on upload.aspx.cs is executed.
     3) The file is actually processed by the Page_Load procedure, and the processed file is saved in the correct location.
  If I upload a normal file (1.5 MB):
     1) The file appears in the root directory where upload.aspx is located.
In Firefox (3.5.7):
  No matter what size the file is, it:
     1) The file appears in the root directory where upload.aspx is located.

I have maxRequestLength="30000" executionTimeout="3000" in the web.config just to be sure.

In the setting object for the constructor I have:
  file_size_limit: "10 MB",
  file_types: ".",
  file_types_description: "All Files",

So my questions are:
  How is the file getting saved in the root directory (and why)?
  Why does Page_Load only execute when I am using IE and uploading very tiny files?

Answer 1

A tiny piece of my previous file uploading solution was lingering in the web.config, and after removing it the odd behavior stopped.