SharePoint 2007 to 2010 upgrade workflow task content type id issue

When upgrading from SharePoint 2007 to 2010 I came across a rather odd issue. A custom workflow was no longer using the custom WrkTaskIP.aspx page to host the InfoPath forms as it did in 2007. On closer inspection this was caused by the tasks created from the workflow not having the right content type (and the custom WrkTaskIP page was referenced in the workflow task content type xml file).