daz, Thank you for your help, kind sir. daz wrote: > You *closed* ZA ? (Not recommended ever, while online, BTW) Yes, it was painful to turn it off, but I'm getting desperate. daz wrote: > Try running this modified version of your script and > report which trace line number you reach. I reach line 272. Unfortunately, except for the file names we picked, my trace file (http://factoad.com/ruby/pptrace_x.txt) is identical to yours (http://factoad.com/ruby/pptrace.txt) up to line 0272, where mine hangs and yours continues. (Here's the diff file: http://factoad.com/ruby/tracediff.txt. Here's the script: http://factoad.com/ruby/io_test_trace.rb ). It hangs when writing the get request string to a TCPsocket object. Does anyone know why this might fail without raising an exception? Any suggestions appreciated... Ken ruby 1.8.2 (2004-12-25) [i386-mswin32] thread started with this email: http://factoad.com/ruby/email.txt