diff --git a/crates/webzjs-wallet/src/bindgen/wallet.rs b/crates/webzjs-wallet/src/bindgen/wallet.rs
index 2d9f6b83..7b29651b 100644
--- a/crates/webzjs-wallet/src/bindgen/wallet.rs
+++ b/crates/webzjs-wallet/src/bindgen/wallet.rs
@@ -297,7 +297,7 @@ impl WebWallet {
         match sync_handler.await {
             Ok(Ok(())) => Ok(()),
             Ok(Err(err_string)) => {
-                tracing::error!("Sync error: {}", err_string);
+                tracing::warn!("Sync error (will be retried by caller): {}", err_string);
                 Err(Error::Sync(err_string))
             }
             Err(panic_error) => {
@@ -396,7 +396,9 @@ impl WebWallet {
             })
             .unwrap_throw()
             .join_async();
-        let txids = sync_handler.await.unwrap();
+        let txids = sync_handler.await.map_err(|e| {
+            Error::Generic(format!("Transaction creation thread panicked: {:?}", e))
+        })?;
 
         let flattened_txid_bytes = txids.iter().flat_map(|&x| x.as_ref().clone()).collect();
         Ok(flattened_txid_bytes)
diff --git a/packages/web-wallet/src/hooks/useWebzjsActions.ts b/packages/web-wallet/src/hooks/useWebzjsActions.ts
index c155b4f9..2217bdf7 100644
--- a/packages/web-wallet/src/hooks/useWebzjsActions.ts
+++ b/packages/web-wallet/src/hooks/useWebzjsActions.ts
@@ -488,7 +488,7 @@ export function useWebZjsActions(): WebzjsActions {
           }
         } catch (syncErr) {
           consecutiveFailures++;
-          console.warn(`Full resync: sync round ${round} failed (${consecutiveFailures}/${MAX_CONSECUTIVE_FAILURES}):`, syncErr);
+          console.debug(`Full resync: sync round ${round} failed (${consecutiveFailures}/${MAX_CONSECUTIVE_FAILURES}):`, syncErr);
 
           if (consecutiveFailures >= MAX_CONSECUTIVE_FAILURES) {
             throw syncErr; // give up after too many consecutive failures
@@ -496,7 +496,7 @@ export function useWebZjsActions(): WebzjsActions {
 
           // Back off longer after failures
           const backoff = SYNC_ROUND_DELAY * Math.pow(2, consecutiveFailures - 1);
-          console.info(`Full resync: backing off ${backoff}ms before retry`);
+          console.debug(`Full resync: backing off ${backoff}ms before retry`);
           await new Promise(r => setTimeout(r, backoff));
         }
       }
diff --git a/packages/web-wallet/src/utils/balance.ts b/packages/web-wallet/src/utils/balance.ts
index 4dafbc32..d850652e 100644
--- a/packages/web-wallet/src/utils/balance.ts
+++ b/packages/web-wallet/src/utils/balance.ts
@@ -7,12 +7,17 @@ function zatsToZec(zats: number): number {
 }
 
 function zecToZats(zecAmount: string): bigint {
+  const trimmed = zecAmount.trim();
 
-  if (!/^\d+(\.\d+)?$/.test(zecAmount)) {
+  if (!/^(\d+\.?\d*|\.\d+)$/.test(trimmed)) {
     throw new Error('Invalid ZEC format: must be positive number');
   }
 
-  const amount = new Decimal(zecAmount);
+  const amount = new Decimal(trimmed);
+
+  if (!amount.isPositive() || amount.isZero()) {
+    throw new Error('Invalid ZEC format: must be positive number');
+  }
 
   if (amount.decimalPlaces() > 8) {
     throw new Error('Maximum 8 decimal places allowed');