that's good advice. delete the folder and when you re-install be very careful to allow the patch to overwrite EVERY file it wants to, along with maintaining the file structure.
with all those previous installations, it is possible to have a mixed up patch installation. one way you can tell, is that your areas load improperly (like you describe) AND items have strange descriptions, some doors that previously opened will not open for you now, etc.
the MOST important thing to remember is that since you DID install the latest patch, you CANNOT go back to an earlier patch.
the patches are not backwards compatible that way. your save games will become corrupted and you will encounter the dreaded ::gasp:: CTD error! (crash to desktop)
::runs her hand over her bald head, remembering the mistakes that caused her hair to fall out::
i speak from experience. it's not a pretty situation.
V***V