I'm sorry to hear about those of you still experiencing AS woes ...
the only thing I would like to add ( maybe it will help ) is ...
pay attention to when you last sync and before retiring the device ... activesync does not go away by itself ... you have to actually "terminate" it ...
the reason I mention this is I'm thinking that AS is not turn on by itself but infact .. it is still left on from the last time you had sync ..
me running X51V + A12 ... after I followed the above advice ... I've been keeping a close eye to investigate and my Axim is behaving quite nicely ... no unpredictable AS at all ( knock on wood !!

)
also ... I did left the "fake server trick" still without deleting it to keep it on "manual"
( also make sure all items are UNCHECK )... it tends to reverts back to "as item arrive" if you delete the server ...but will kept at "manual" if you keep the server.
and I also unselect the dates in peak times and set the start and end time to be the same so they cancel each other out ( covering all the bases

)