Still nothing in the newsgroups ...
log files here show "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30)"
I can't tie this issue into any of the (seemingly millions of) IE7 complaints, so really not sure if the typical "remove cookies, clear cache and history, re-boot, etc." would really be useful ....
Your ISP upgrading things could be a factor, but ... exactly how, I'm not at all sure of. Wild and idiotic guess would be like a scenario where they have ended up with a couple of routers working in parallel, where your browser request is somehow being handle by two routers, both passing on amd handling the data. The additional ramificatins of such a situation are simply mind-boggling, so ... let's leave that as simply silly ....
On the other hand, we sure are running shy on the "me too" posts ....
As far as the 'confusion factor' .... it'll take some time, but .... some of this was addressed in
Held Mail Enhancement Request, Color Options for Held Mail Page which infortunately contains multiple links back to other ancient Topics / Discussions ..... as stated, the 'mailsc' account/connection is to IronPort controlled computers on the west coast, but the e-mail data itself is actually stored on JT's hardware on the east coast .... lot's of handshaking going on there, never mind adding in 'your' connection / display bringing it all together on your screen ...