Not sure if this is a design flaw or a Win quirk. I have an image editing class where I can crop/resize/filter an image. It creates a unique temp file in a specified folder using the source filename appended with the session_id. Currently it has a single level of undo that simply unlinks the temp file. Various editing methods check for the existance of this temp file and if it doesn't exist, it uses the source file for any edits. On my system, Win2k Server/Apache2/PHP5, undo always returns true. However, the temp file will still be in the temp folder for up to 30s or more even though it will not allow me to delete it or view properties. This is causing an exception to be thrown if I try to edit the image immediately after an undo operation. Apparently, the methods are still treating it as a valid file even though it was unlinked. It works as intended on my webhost using nix/apache2/PHP4.3. Anyone had a similar problem?