diff --git a/core/soulseek_client.py b/core/soulseek_client.py
index a5062585..9dfcedd0 100644
--- a/core/soulseek_client.py
+++ b/core/soulseek_client.py
@@ -2026,6 +2026,13 @@ class SoulseekClient(DownloadSourcePlugin):
         """
         from database.music_database import MusicDatabase
 
+        if not results:
+            return []
+
+        # Issue #652: drop candidates on the quarantine record BEFORE ranking,
+        # so a previously-quarantined source can't win the quality picker by
+        # superior bitrate and re-trigger the same failed download in a loop.
+        results = self._drop_quarantined_sources(results)
         if not results:
             return []
 
diff --git a/database/music_database.py b/database/music_database.py
index 3b6a17fb..492440d5 100644
--- a/database/music_database.py
+++ b/database/music_database.py
@@ -664,7 +664,6 @@ class MusicDatabase:
             """)
             cursor.execute("CREATE INDEX IF NOT EXISTS idx_lh_event_type ON library_history (event_type)")
             cursor.execute("CREATE INDEX IF NOT EXISTS idx_lh_created_at ON library_history (created_at DESC)")
-            cursor.execute("CREATE INDEX IF NOT EXISTS idx_lh_verification_status ON library_history (verification_status)")
 
             # Migration: add download_source column
             cursor.execute("PRAGMA table_info(library_history)")
@@ -677,6 +676,12 @@ class MusicDatabase:
                     cursor.execute(f"ALTER TABLE library_history ADD COLUMN {_col} TEXT")
                     logger.info(f"Added {_col} column to library_history")
 
+            # Index on verification_status — MUST come after the ALTER above:
+            # on a fresh DB the base CREATE TABLE has no verification_status
+            # column, so indexing it before the migration adds it raises
+            # "no such column: verification_status" and aborts DB init.
+            cursor.execute("CREATE INDEX IF NOT EXISTS idx_lh_verification_status ON library_history (verification_status)")
+
             # One-time backfill: derive verification_status for history rows
             # written before the column existed (or by pipeline exits that
             # missed it) from the acoustid_result those imports already