new subdomain sites - corruption

this is probably hard to diagnose problem .. hopefully not ... it is probably associated with Domain Mapping... and Multi-Domains... but maybe not

I have a WP 3.5 multisite subdomain network with multi-domains and domain mapping, all plugins updated. so far it seemed to work reasonably well... but...

I added a new subdomain site to one of the multidomains... seemed okay... but for some mysterious reason that site thinks it is another site... this is even hard to explain:

mainsite.com
subdomain.mainsite.com has a multidomain samplesite.com
so I add new site to samplesite.com
problem.samplesite.com
looks like it was added okay... but when go to dashboard or visit site, problem.samplesite.com goes to anothersite.mainsite.com...

BIGGEST CLUE... anothersite.mainsite.com is a site that used to have domain mapping - anothersite.com, but I deleted the domain mapping to just use anothersite.mainsite.com

I tried adding another test site with anothersite.mainsite.com deactivated. nope, same problem -- newtest.samplesite.com thinks it is anothersite.mainsite.com

CLUE: with anothersite.mainsite.com "deactivated" - visiting the site, it displays and is not deactivated. both dashboard and live site - it is not deactivate

I added a new multidomain ... examplesite.com added another test site... test.examplesite.com still goes to anothersite.mainsite.com...

CLUE I added a new test site to mainsite.com = test.mainsite.com and it resolves correctly. so it is the multi-domain sites with the problems adding new subdomain sites.

Maybe not a clue, but.. when creating the site I noticed that templates were not offered - and New Blog Template settings have been deleted somehow during updates. but ultimately I don't think the blog templates have anything to do with it.

in order to test Domain Mapping as the culprit I went back to the original anothersite.com... and reestablished it. it resolves correctly - even with the site "disabled".

BIGGEST CLUE2... but guess what... with Domain Mapping restablished for anothersite.com --- adding a new site to samplesite.com... a Different site that had recently had domain mapping changed is now chosen as the identity

the new test site test4.samplesite.com now thinks it is differentsite.mainsite.com

but the sites created before anothersite.mainsite.com was reverted, they still think their dashboard and site is anothersite.mainsite.com

I know this one is a brain bender, but my network is now handicapped... and I'm pretty sure Domain Mapping combined with Multidomains is to blame... but could be wrong of course

help and advice greatly appreciated.

BTW: I really can't see disabling domain mapping to test this... my network would be down.