Hey,
There is a way to "publish" more than one version of the form to the same form library and have the data files understand which version of the form to go to.
For example:
You publish the initial version of form 1001 to Sharepoint naming the form library 1001 and it's description "Test My Versions".
In that library under the forms folder will be "template.xsn". If you take a closer look at the general properties of the form library, the template name can be overwritten.
To add another version of form 1001 to the same library.....go to the 1001 Form library in Sharepoint and drill down to the "Forms" folder within that library. Copy a new version of the form (name it something else like 1001_20060725.xsn) to the forms folder. Click on the general properties for the form folder in Sharepoint and rename the start template from template.xsn to 1001_20060725.xsn. Save your settings
Open the 1001_20060725.xsn in Design mode from a location other than Sharepoint and publish the form to the 1001 form folder. The form folder will now have both the template.xsn and the 1001_20060725.xsn
Data files that were dependent on template.xsn will load the "older" template. Anyone clicking on the link for "Test My Versions" form will receive the new 1001_20060725.xsn version.
The key to keeping more than one version of the form in the same library is changing the template name in the General properties of the Form Folder in Sharepoint BEFORE publishing the new version of the form.
Mary