diff -purN cacherouter-rc1/engines/file.php cacherouter-rc1-unlink-patch/engines/file.php
--- cacherouter-rc1/engines/file.php	2009-09-05 06:03:25.000000000 -0700
+++ cacherouter-rc1-unlink-patch/engines/file.php	2009-09-18 10:28:02.000000000 -0700
@@ -129,7 +129,9 @@ class fileCache extends Cache {
             // only delete the cache file once we obtain an exclusive lock to prevent
             // deleting a cache file that is currently being read.
             if (flock($fp, LOCK_EX)) {
-              unlink($file->filename);
+              if (file_exists($file->filename) {
+                unlink($file->filename);
+              }
             }
           }
         }
@@ -146,7 +148,9 @@ class fileCache extends Cache {
             // only delete the cache file once we obtain an exclusive lock to prevent
             // deleting a cache file that is currently being read.
             if (flock($fp, LOCK_EX)) {
-              unlink($file->filename);
+              if (file_exists($file->filename) {
+                unlink($file->filename);
+              }
             }
           }
         }
@@ -157,7 +161,9 @@ class fileCache extends Cache {
         // only delete the cache file once we obtain an exclusive lock to prevent
         // deleting a cache file that is currently being read.
         if (flock($fp, LOCK_EX)) {
-          unlink($filename);
+          if (file_exists($filename) {
+            unlink($filename);
+          }
         }
       }
     }
@@ -253,7 +259,9 @@ class fileCache extends Cache {
           // We need an exclusive lock, but don't block if we can't get it as
           // we can simply try again next time cron is run.
           if (flock($fp, LOCK_EX|LOCK_NB)) {
-            unlink($file->filename);
+            if (file_exists($file->filename) {
+              unlink($file->filename);
+            }
           }
         }
       }
@@ -267,7 +275,9 @@ class fileCache extends Cache {
             }
             fclose($fp);
             if ($cache->expire != CACHE_PERMANENT && $cache->expire <= time()) {
-              unlink($file->filename);
+              if (file_exists($file->filename) {
+                unlink($file->filename);
+              }
             }
           }
         }