Thanks to some features kindly incorporated by Erel into Basic4ppc version 6.80 I've now completed my debugging suite for optimised compiled applications. Up to now when an error occurred in an optimised compiled application there was no indication of the error line number. Now, using my DebugRecompiler utility, when an error occurs on either desktop or device the error line number can be established. But it's better than that! Up to now (apart from earlier version of my Debug library) there has been no real ability to debug applications on the device apart from adding Msgbox statements. Now when my DebugRecompiler is used with the latest version of my Debug library, included here, optimised compiled applications running on both desktop and device may be halted, single stepped, breakpointed and have their properties and variables inspected and changed and their methods and Subs invoked. The Debug archive includes an application, DebugDemoLegacy, that demonstrates the Debug library use with IDE or legacy compiled applications. The DebugRecompiler archive has an application, DebugRecompilerDemo, that demonstates debugging an optimised compiled app and also a tutorial to walk you through the first steps in using DebugRecompiler. This will only work on Basic4ppc version 6.80 or later. EDIT:- Version 1.7 of the Debug library now has a Watcher that works in the IDE and when legacy compiled on both device and desktop as well as when optimised compiled. See post #6 for details.