ASP File Changes - Drops ASP Code

I have written a classic ASP calendar that has been on my organization's website for a couple of years now, and it has worked fine.

I do all of my writing to files on my hard drive, then when the files are working properly, I upload the files to the server. Therefore, the files on my hard drive should be identical to the ones on the server. This has worked fine in the past - I have had two fully functional calendars, one on my hard drive, the other online. Until now, they both looked and worked identically.

Now, I'm trying to modify the main file, "calendar.asp". It no longer works, and the online copy still works flawlessly. When I looked at the local file (calendar.asp), all of the ASP code had been stripped from the file. Of course, the online copy is still intact and working.

The only editor I have used on these files is Notepad (actually, Notepad ++, an enhanced Notepad). I would understand if I had tried to edit the files with Frontpage (I'm using Frontpage to upload files to the server, but that's all I use it for), but these local files haven't been touched by Frontpage.

What Gives? How can a file selectively remove it's own code and disable itself??!!!

I try exporting the files from the server, and though the server files still have their ASP code, the browser can't find one of the include files, which is plainly in the same folder as the calendar.asp file. The file "adovbs.inc" is no longer reachable from my hard drive, even if I export ALL of the files in the "calendar" folder to my hard drive.

What can be hoseing up my local files, and how can I prevent it? Although I have downloaded ALL of the files from the online copy to my hard drive, why do the files behave differently than they do online? What kind of trickery is this?