i dint added web context access to any user group for the resource group
it happened in front end for anonymous users and i got number of mails saying few pages r not accessible for them which i added to resource group
have searched modx forums IRC and ended up with adding web context access and it worked
Modx is wonderfull but sometimes it gives unpredictable results it.may range from cache issues to template changes
yesterday my client moved from modx as his main site home pages going offline more often
in bug trackers iam seeing it as fixed but its still happening in 2.2.none of the solutions mentioned worked
modx behaving differently for different servers i know you may not replicate these bugs in ur server
have worked with all major CMS but to be honest i never found so many bugs in other CMS that i had in modx.no offence...
but i still love Modx and iam addicted to it

.it have the power to make web better but it needs to work on any server and any browsers correctly for the first time and every time
Johny you cant restrict one chunk or one element access.you can set access on element based.like chunks .snippets etc and with categories
Regards