Start Editing Folder Gone

I'm in Arcmap 9.2 SP4 with a ArcInfo License. We have a mxd with a bunch of layers of data in it. Usually you click start editing and then select the folder with the feature class you want to edit (the location of a personal geodatabase) and then start editing. The problem is that the folder where the feature class we want to edit does not appear anymore. The feature class is still under the layers and usable. The location of it has not changed. How can I edit that list, refresh it, or somehow get that folder back in there? Thanks.

Actually I did. I ended up restoring the .mxd from a earlier backup date and that did it. Something got messed up and the restore was the only way I ever found of fixing it.

I was having a similar problem and found a solution. I was trying to edit data using an old mxd. The data was all in the same SDE gdb yet when I clicked start editing there were 3 'Sources' of the same SDE gdb available for editing (in the Start Editing window). When I selected one and it showed which layers and tables were available for editing, the layers that appeared under the target menu were different. My boss told me there are 2 ways to connect to an SDE gdb; one being a direct connection. By changing my connection properties to connect 'directly' the issue was resolved. I had to rebuild the mxd but now all the layers in the maps are available for editing and there is only one SDE 'Source' showing in the Start Editing window. I hope this helps someone else. It was extremely frustrating ans something tech support could not help with.