Hello,
Can you please tell me the version of mDigger you have? The latest version is 7.6.2001.7. If you have an earlier version, please update at http://www.mdigger.com/download.aspx.
When you save the package, please make sure that you are saving it to the desired folder. And when you open the saved package, make sure you are looking in the same folder. Sometimes, it is easy to overlook this little issue.
Also please let me know whether ALL of your packages can't be saved, or only SOME of the packages can't be saved.
Thank you,
mDigger Team