Hi,
I think your comment points out a fact about software upgrades/conversions/modifications in general, when they concern the development environment for applications that are in production, or are otherwise valuable. Having gotten burned myself in similar circumstances, your comment is a reminder to preserve important projects/applications in the form that works. Don't assume that a later version or upgrade to the IDE can only make things better - or that you can always undo the conversion to get back to where when things worked right. Also don't assume that an update or upgrade wouldn't do any conversion you don't intend. Even if the new version is polite enough to ask you whether you really, really want to convert the application, and even if it warns you about possible consequences, all that may get lost in the blur of warnings, options and general information overload.
Maybe the lesson is to always take steps to preserve a working copy of your application. It's probably best that the archived copy be somewhere untouchable by the IDE - in case it does you the favor of converting all the files of a given file type that it can find; so don't let it find your archive.
BRN..