Running 1.3.6 (heavily modded)

Hello,
The Admin for our site created a series of subcategories and moved products into them. These products all lost their information to the download file. The Download Attribute was still there but the file information (xxx/filename.zip) was not. It had gone missing out of the DB also.

I assume this is not default behavior. I could not find any other entries on this with a search. Any ideas? We lost 300+ links that must all be redone.

Thanks for any help,
Bill