Solved! I think.
It's taken quite some time but I think I found the problem: theninternet guest account used by IIS, under which ASP pages run, must benpermissioned on the file system not through the InternetnService Manager administrative tool. It seems obvious now.
Two interesting things: First, IIS seems to wholly rewrite its logsnwith each entry so tailing them is not possible. Tried it with a threenimplementations of tail and it doesn't work. It's as if it copiesneverything to a new file, unlinks the old one and renames the new onento the old name. Weird. Second, and this is probably in the “Well,nduh!” category for Windows developers, is that there is a nice littlenserver-side debugger for these scripts with break points, stack trace,netc. in IIS and if enabled will emit useful information when annexception occurs. Neat.