diff --git a/app.py b/app.py
index 4417201..6fabc1c 100755
--- a/app.py
+++ b/app.py
@@ -766,6 +766,9 @@ def serve_file(subpath):
     if not os.path.isfile(full_path):
         app.logger.error(f"File not found: {full_path}")
         return "File not found", 404
+    
+    filesize = os.path.getsize(full_path)
+    filename = os.path.basename(full_path)
 
     # 2) Prep request info
     mime, _ = mimetypes.guess_type(full_path)
@@ -871,7 +874,12 @@ def serve_file(subpath):
         cache_key = hashlib.md5(subpath.encode('utf-8')).hexdigest()
         cache_dir = os.path.join(cache.directory, cache_key[:2])
         os.makedirs(cache_dir, exist_ok=True)
-        cache_file_path = os.path.join(cache_dir, f"{cache_key}.tmp")
+        fd, cache_file_path = tempfile.mkstemp(
+            prefix=f"{cache_key}_",
+            suffix=".tmp",
+            dir=cache_dir
+        )
+        os.close(fd)
         
         # Start copying to our cache file in chunks
         def copy_to_cache_chunked():
@@ -886,6 +894,11 @@ def serve_file(subpath):
                 
                 # Once complete, register with diskcache for proper management
                 try:
+                    if subpath in cache:
+                        if os.path.exists(cache_file_path):
+                            os.remove(cache_file_path)
+                        app.logger.info(f"Cache already populated for {subpath}, skipped duplicate registration")
+                        return
                     with open(cache_file_path, 'rb') as f:
                         cache.set(subpath, f, read=True)
                     # Remove our temp file since diskcache now has it
@@ -924,9 +937,6 @@ def serve_file(subpath):
             abort(503, description="Service temporarily unavailable - cache initialization failed")
 
     # 6) Build response for non-image
-    filesize = os.path.getsize(full_path)
-    filename = os.path.basename(full_path)
-    
     if as_attachment:
         download_name = filename
         mimetype = 'application/octet-stream'
@@ -952,7 +962,10 @@ def serve_file(subpath):
                         # No data available yet, wait a bit
                         time.sleep(0.1)
         
-        response = make_response(generate())
+        if request.method == 'HEAD':
+            response = make_response('', 200)
+        else:
+            response = make_response(generate())
         response.headers['Content-Type'] = mimetype
         response.headers['Content-Length'] = str(filesize)
         response.headers['Accept-Ranges'] = 'bytes'
@@ -978,6 +991,9 @@ def serve_file(subpath):
             response.headers['Content-Disposition'] = 'inline'
 
     response.headers['Cache-Control'] = 'public, max-age=86400'
+    
+    if request.method == 'HEAD':
+        response.set_data(b'')
 
     # 7) Logging
     if do_log:
diff --git a/auth.py b/auth.py
index b7e524e..847fd4c 100644
--- a/auth.py
+++ b/auth.py
@@ -152,17 +152,17 @@ def require_secret(f):
         for token_in_session in session.get('valid_tokens', []):
             try:
                 token_item = decode_token(token_in_session)
-                print(f"DEBUG: Decoded token: {token_item}")
+                # print(f"DEBUG: Decoded token: {token_item}")
                 for folder_info in token_item.get('folders', []):
-                    print(f"DEBUG: Adding folder '{folder_info['foldername']}' -> '{folder_info['folderpath']}'")
+                    # print(f"DEBUG: Adding folder '{folder_info['foldername']}' -> '{folder_info['folderpath']}'")
                     session['folders'][folder_info['foldername']] = folder_info['folderpath']
             except Exception as e:
                 print(f"ERROR: Failed to process token: {e}")
         
         # Mark session as modified to ensure it's saved
         session.modified = True
-        print(f"DEBUG: Final session['folders'] keys: {list(session['folders'].keys())}")
-        print(f"DEBUG: session['valid_tokens']: {session.get('valid_tokens', [])}")
+        # print(f"DEBUG: Final session['folders'] keys: {list(session['folders'].keys())}")
+        # print(f"DEBUG: session['valid_tokens']: {session.get('valid_tokens', [])}")
 
         # 6) If we have folders, proceed; otherwise show index
         if session['folders']: