Ghost levels (missing level information) and possibly corrupt microstation files?

Hi, I have an issue with Microstation files losing level information and was wondering if others have experienced the same issue. The problem appears to be inconsistent and occurs once every other week or so.

The file appears to work fine until it is closed and reopened. Upon reopening, level information will be stripped leaving what I can best describe as ghost levels. They no longer have a name in the element information dialog, just blank. However, the message center recognizes that an element is selected and shows an integer. Also the level color defaults to white and random elements are missing. This seems to impact files at random (other files within the same folder are usually fine).

For example, I go to open a file with multiple levels, all of which have changed to white since I was last in the file. The level used to be called: "Erosion Control Plan Text CELL" but is now showing as "4" in the message center and blank under element information. Several elements are now missing. This was only one file in a folder of about 30 (the others were not corrupt).

Any thoughts?

Thank you!