I have a colleague (Nicolas Corchia - Sogeti) who came into my office with a migration 2007>2010 problem.
The 2007 Codes analysed a webpartpage in order to find the ListViewWebpart included in it in order to modify them...
Well... after the migration...no more listViewWebpart were found... He came out with the fact that sharepoint automatically changed the listviewPart by the new XsltListViewWebPart class.
Because nicolas is a good developer ;-) he found out that the problem was wimply a casting problem obliging him to recast the webparts in the code itself!
Find more in : http://msdn.microsoft.com/fr-fr/library/ff806162.aspx
Thanks to a problem raised by Nicolas Corchia (Sogeti),