In the school I work in we have a large number (500+) of Windows 7 laptops on a Meru Wireless system and Server 2008 R2 Servers. We have an appalingly large failure rate where a student or staff member tries to logon (to the laptop joined to the domain) and is met by "There are currently no logon servers available to service the logon request". I've seen this question and this one and while removing and re-joining to the domain works, it's highly time consuming, irritating, and we (I) have more important things to concentrate on. The only MS KB article I can find is regarding a read-only domain controller (which ours isn't) and I'm at my wits end.

Ultimately, is there a definitve cause and answer to this or am I stuck removing and re-joining the laptops?