Index: uc_donation.module
===================================================================
--- uc_donation.module
+++ uc_donation.module	(working copy)
@@ -589,10 +589,9 @@
   $cid = !(is_null($cid) || empty($cid)) ? $cid : uc_cart_get_id();
 
   $prev_data = $data['data'];
-  unset($data['data']);
 
   if ($qty < 1) {
-    uc_cart_remove_item($nid, $cid, $data);
+    uc_cart_remove_item($nid, $cid, $data['data']);
   }
   else {
     db_query("UPDATE {uc_cart_products} SET qty = %d, changed = %d, data = '%s' WHERE nid = %d AND cart_id = '%s' AND data = '%s'", $qty, time(), serialize($data), $nid, $cid, serialize($prev_data));