diff -r b83c7a738eb8 -r aa73039d5d14 src/Tools/jEdit/src/proofdocument/session.scala
--- a/src/Tools/jEdit/src/proofdocument/session.scala	Mon Jan 04 19:42:35 2010 +0100
+++ b/src/Tools/jEdit/src/proofdocument/session.scala	Tue Jan 05 18:23:15 2010 +0100
@@ -151,7 +151,8 @@
       }
       else if (result.kind == Isabelle_Process.Kind.EXIT)
         prover = null
-      else if (result.kind != Isabelle_Process.Kind.STDIN) bad_result(result)
+      else if (result.kind != Isabelle_Process.Kind.STDIN && !result.is_ready)
+        bad_result(result)
     }