aakk9999 - 6:06 pm on Oct 9, 2012 (gmt 0)
We cannot prevent the change but only to decide the best practices to drive the same traffic and downloads that the previous one is getting to this new URL.
Permanent redirect (301) from the old URL to the new one. This should bring any visitor that requests the old page to the new page (including search traffic, type-in traffic, bookmarks, external links, etc.)
Internally link to the new page.
Keep permanent redirect up forever.
And make sure the redirect from the old to the new URL is in one hit (no chain redirects).