Trust relation issue from AD to Kiosk PC's

I'll start off by introducing you to how our network is made, we have about 100-150 computers all around a rather big area (different buildings etc.) acting as something similar to "Kiosk PC's", they only got a web browser and automatically logs on, any other access is stripped, and this web browser is forced to full screen so they can really just go around on our internal web page (This is the pure intention.)
These PC's are running Windows Embedded, and according to MS that is pretty much "XP SP3 light", a stripped down version of XP SP3.
Our domain controller is running Windows Server 2008 R2.
Upon startup of these clients, they sign on to their individual account name in the domain (Yes, they use domain users and not local users.) This logon is automated upon startup.
Now, to the problem, all along, and worst recently, is that more and more of these computers looses the trust relationship to the AD, giving the AD System errors event 5722, 5805, 5723, 5722 - All NETLOGON related, and there is even ID 4 - Security-Kerberos, now this is getting further and further away from my basic understanding of how computers work together.
Now, I've worked on this day out and day in for weeks now, and my coworkers for even longer, we've investigated into any and everything on how to fix this on machines that has the problem, as this seems to be the root cause of loosing trust relationship to AD. So for months now our IT department has been investigating into scripts and systems on how to fix this trust relationship with these computers, tried everything from nltest, netdom, etc. but the basic examples and instructions on resetting the trust relationship gives us "Access is denied." Which matches what the event logs tells us.
Now, removing, changing name and adding back to domain fixes this trust relationship, but that is not a working solution for us. We need for starters to figure out why these computers keeps loosing trust relationship to the AD and fix that, then we can start working on how we can sort out the computers already having a trust issue with the AD.

So, what I'm asking is, what triggers these events, why does these computers keep loosing trust relationship to the AD - and how do we fix this?

Thanks in advance for any and all help,
Best  regards,
Kristoffer Kjelvik



(Written in english so everyone can understand, answers in english are preferred but I understand norwegian, swedish and danish as well.)