Hi Zinc,
Im only slightly confused as to that last bit, but no matter.. The fix I have for you is the same no matter what that last question was.
I want you to close MX, open your folder in Program files. Usually its C:\Program Files\WinMx
Inside you will see a file named library.dat (if you use 3.53) or lib4.dat (if your on 3.54 beta 4) Which ever you see there or both, Id like you to delete.
Next Start up WInMX and reshare the files you'd like to share.
The problem with Scan For Media is not really that you may 'download' something bad to the wrong drive, but that your sharing information and files that are not ones you want just anyone getting ahold of.
Deleting those files mentioned above only deletes the 'path shortcuts' mx has stored to find the files, it wont delete any actual files. If your not sure how to share on your version of MX have a look at the Tutorials pages and look for Sharing on.. (insert your version here) and make sure your ok with what is shared.
Hope this helps and if you need any further assistance dont hesitate to ask us...