diff --git a/CHANGELOG.md b/CHANGELOG.md
index f3933cf..c98476b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.13.41 (2026-04-29)
+
+### Debug logging for sector-0 regression diagnosis
+
+- Add debug logging to Drive::read and Disc::copy first reads.
+- No functional changes.
+
 ## 0.13.40 (2026-04-28)
 
 ### Pass 1 pure ECC-block sweep, transport-failure abort, mapfile-based recovery
diff --git a/Cargo.toml b/Cargo.toml
index e3a26d7..bb6ba4f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "libfreemkv"
-version = "0.13.40"
+version = "0.13.41"
 edition = "2024"
 rust-version = "1.86"
 license = "AGPL-3.0-only"
diff --git a/src/disc/mod.rs b/src/disc/mod.rs
index c215f9e..7d7d490 100644
--- a/src/disc/mod.rs
+++ b/src/disc/mod.rs
@@ -1338,6 +1338,20 @@ impl Disc {
                 let block_count = (block_bytes / 2048) as u16;
                 let recovery = !opts.skip_on_error;
 
+                if read_ok_count + read_err_count < 3 {
+                    tracing::info!(
+                        target: "freemkv::disc",
+                        block_lba,
+                        block_count,
+                        block_bytes,
+                        recovery,
+                        skip_on_error = opts.skip_on_error,
+                        batch,
+                        total_bytes,
+                        "Disc::copy first reads"
+                    );
+                }
+
                 let read_result = reader.read_sectors(
                     block_lba,
                     block_count,
diff --git a/src/drive/mod.rs b/src/drive/mod.rs
index 9f90ee4..63febc3 100644
--- a/src/drive/mod.rs
+++ b/src/drive/mod.rs
@@ -444,6 +444,14 @@ impl Drive {
         } else {
             crate::scsi::READ_TIMEOUT_MS
         };
+        tracing::debug!(
+            target: "freemkv::drive",
+            lba,
+            count,
+            recovery,
+            timeout_ms,
+            "Drive::read enter"
+        );
         let cdb = [
             crate::scsi::SCSI_READ_10,
             0x00,
@@ -467,6 +475,14 @@ impl Drive {
             Err(Error::Halted) => Err(Error::Halted),
             Err(e) => {
                 let (status, sense) = extract_scsi_context(&e);
+                tracing::warn!(
+                    target: "freemkv::drive",
+                    lba,
+                    count,
+                    inner_error = %e,
+                    scsi_status = status,
+                    "Drive::read checked_exec failed"
+                );
                 Err(Error::DiscRead {
                     sector: lba as u64,
                     status: Some(status),