With CVS HEAD (19 October 2005 Australian morning) the following minimal modifications to the HGL library give a runtime error in the "GTest.exe" example program:=======================================...handleEvent: Before getMessage.handleEvent: Before yield.GTest.exe: internal error: resumeThread: thread not found Please report this as a bug to glasgow-haskell-bugs@haskell.org, or http://www.sourceforge.net/projects/ghc/=======================================Without those two putStrLn () calls, none of the three example programs "GTests.exe", "Tests.exe" or "HelloWorld.exe" displays a Window.With those two putStrLn () calls, all three example programs present their windows and both "Tests.exe" and "HelloWorld.exe" appear to run perfectly (although note that I have not seen them running at all other than in these tests).CheersMike Thomas===================================================================RCS file: /home/cvs/root/fptools/libraries/HGL/Graphics/HGL/Win32/WND.hs,vretrieving revision 1.9diff -r1.9 WND.hs130a131> putStrLn "handleEvent: Before yield."133a135> putStrLn "handleEvent: Before getMessage."