default.aspx page reverting

I am the administrator for a custom SharePoint application.  The application is developed in-house.  There appears to be an issue with one of our current solutions.  The solution should be updating the default.aspx page under the STS template. It appears that when I deploy this solution, it works fine for a short time - however, at some point in time, the default.aspx page under "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\SiteTemplates\sts" reverts, and the default page that came shipped with sharepoint returns.

The shipped custom default.aspx adds a custom zone to the page layout, and the result is that any user who has placed a web part in the zone has their web part shifted to another zone, messing up the page layout.

At the suggestion of the development team, I copied in the default.aspx from the solution file.  This corrected the issue - but again, it was only for a short time.  I go back and look now and it has reverted back to the same date/filesize, etc. as a backup I took of the default.aspx before deploying the one from the solution.

Is there a way that I can update the SharePoint content DB with the appropriate default.aspx, after deploying it manually?  I think what is happening is that the SharePoint content DB is deploying it's copy from the database - so i would like to update the database so that the solution deployed default.aspx becomes the authoritative copy.

Thank you