issues using vim under screen

[ping]

I'm a heavy vim and screen user, and I find it real convenient to combine this two great tools -- running vim under screen.
but there is one annoying issue about this method in my PC: from time to time I find I can't copy/paste X/system buffer from/to vim anymore- to be more specific: the issue is I can't issue keybind "+p (or "*p) or "+y(or "*y) in vim...this make it hard to use vim under screen. I know there is screen solution of copy/paste among sessions, but I really want to make vim communicate with other programs outside of screen more directly.

and, the even strange symptom is: it started to be good, but then after some days, I can't do it anymore. But at this time if I start a new fresh screen and run vim inside it, the copy/paste actually works. this happened for a couple of times. I guess the issue will always appear after some time I started my vim+screen sessions...

anyone use vim under screen and had any experiences on this?

I did some research, previously I had an impression that this works for me,  but it looks I'm now still having this issue from time to time.
http://vim.wikia.com/index.php?title=GNU_Screen_integration

and this plugin seems unrelated to my issue.
http://www.vim.org/scripts/script.php?script_id=2711

thanks in advance!