Getopt-Long-2.38 is stricter about what it allows.

diff -Nuar mytop-1.6.orig/mytop mytop-1.6/mytop
--- mytop-1.6.orig/mytop	2009-04-10 00:47:31.007111359 -0700
+++ mytop-1.6/mytop	2009-04-10 00:50:39.875391905 -0700
@@ -153,7 +153,7 @@
     "idle|i"              => \$config{idle},
     "resolve|r"           => \$config{resolve},
     "prompt!"             => \$config{prompt},
-    "long|!"              => \$config{long_nums},
+    "long!"               => \$config{long_nums},
     "mode|m=s"            => \$config{mode},
     "sort=s"              => \$config{sort},
 );