Arhh, you mean in the SMS console. I thought you meant in the normal File System?
So in the Admin Console, you are just using Packages > Package > right click > Delete > Next > No, go ahead and delete > ok?
Never heard of any problem with this, unless for some reason, one of the files in your package folder (on your normal file system) has been locked.
Check your process list, make sure you haven't somehow got a hidden system process running the program in the package. Or, if you have Run from Distribution point set, rather than always download to client, and your main site server is also your main DP, and a client has tried to run the package, and has hung on one of the operations, then the file will also be locked. If this is the case, you would be able to tell, because if you navigate to your SMSPKG$ folder (or what ever its called, cant remember off the top of my head right now) and try and open the respresenative package that you are having problems with in the AdminConsole, and try and delete the files from in there, you will get an error saying that blahblah.blah is in use and cannot be deleted. You will now know your culperate (sp?).
Hope this Helps.
Neil J Cotton
njc Information Systems
Systems Consultant