Index: __init__.py
===================================================================
--- __init__.py	(revision 6660)
+++ __init__.py	(working copy)
@@ -112,7 +112,10 @@
             # or {'name': 'blah'} for POST fields
             # We assume all uploaded files have a 'filename' set.
             if 'filename' in name_dict:
-                assert type([]) != type(submessage.get_payload()), "Nested MIME messages are not supported"
+                #assert type([]) != type(submessage.get_payload()), "Nested MIME messages are not supported"
+                _payload = submessage.get_payload()
+                if type([]) == type(submessage.get_payload()):
+                    _payload = submessage.get_payload(0).as_string()
                 if not name_dict['filename'].strip():
                     continue
                 # IE submits the full path, so trim everything but the basename.
@@ -123,7 +126,7 @@
                 FILES.appendlist(name_dict['name'], FileDict({
                     'filename': filename,
                     'content-type': 'Content-Type' in submessage and submessage['Content-Type'] or None,
-                    'content': submessage.get_payload(),
+                    'content': _payload,
                 }))
             else:
                 POST.appendlist(name_dict['name'], submessage.get_payload())