Hmm, do you mean the 3.3v line "slowly rises from 0 to 3.3v" like 0.5v, 1v, 2v, etc. or that it rapidly jumps from 0 to 3.3 but it takes a long time to come back on?
I've done some testing over lunch and discovered a very interesting behavior on the Portable.
If you put it to sleep, wait a...