DU4 Issue: phone randomly switches in and out of Skinner mode

[consider_this]

2. To answer your questions...

I am never getting the 'lack of stylesheet' plain text. It just decides to go to DU4 default look and then later may go back to Skinner.
I checked my account settings on the phone - they did say Skinner, and one time I tried 'saving' the account settings from phone - even though i did not change them at all, but it made no difference.
Before I sent my report I was lamenting the DU4 default and wondering if there was any way to get out of it, then I when i clicked a post or a nav button (sorry I cannot recall which) it swapped back to Skinner - but as I say, this happened a few times.

I hope the info helps - I know you have a lot to chase down in such issues, and if I have any further observations about when and how this happens, I will be sure to report back so that it may be of help.
Thanks!!!