Page TRP_Code_Snippets makes use of the CODE plugin.
Where the code snippet includes the GROUP Plugin, the output of the CODE plugin is being truncated. For example see the section titled "Restrict Part of Wiki Page Content".
This worked OK on v4.3 prior to the upgrade to v6.7
This is a TW bug in v6.7 and also in ??v8.x?? as used at dev.tiki.dev - see BIR_B_4239_GROUP_breaks_CODE for bug tracking
Note - On 24Jun2013, the content of page TRP_Code_Snippets was split across two new subpages TRP_Code_Snippets_Part1 and TRP_Code_Snippets_Part2. Because of the adverse impact of this bug, the GROUP plugin which was protecting the whole page has been removed from TRP_Code_Snippets_Part2 so that the content is meaningful to registered users.
NB The bug remains, this is just a work-around employed on this particular page.