If you try to publish an InfoPath form to a Site Content Type while using an explicit path you will run into an error when it tries to retrieve site columns.
This is stated as something that will be resolved in SP2 for WSS 3.0/MOSS 2007 by community but I can find no official statement declaring that it is on the list of fixes for the feb-april timeline Microsoft has set for SP2.
In my humblest of opinions after using explicit paths for some time and experiencing many issues with it (some navigation things also don't work as designed) I would recommend avoiding explicit paths when possible. (Until post SP2, in theory.)
Here are a few community references:
- http://sheetal-d.spaces.live.com/blog/cns!237C3DEA7120098B!649.entry
- http://www.yeschandana.com/category/InfoPath.aspx
- http://social.msdn.microsoft.com/Forums/en-US/sharepointinfopath/thread/32f3a039-b5d0-4805-be04-388f80799da2/
Hope this helps,
Richard Harbridge