Repeat what I said in another thread:
Are you using python OpenCL (poclbm) in guiminer? If so, this problem has been happening for everyone in the last few days. See https://bitcointalk.org/index.php?topic=1334.msg732164#msg732164
Basically it shows that you are mining but the shares are not being submitted.
Anyway, the fix is coming up in Windows so just switch to Phoenix in guiminer or get cgminer for the time being. If you need direction for switching to phoenix, which is what I'm doing now, just ask.
BTW, I've also heard that using the older guiminer version works but have not tried this.
Thanks for the quick response.
I've tried running phoenix but it just opens real quick then closes. So, I guess I'll need to help getting phoenix set up.
Edit: Its still showing no shares too, has this been common for everyone else as well?
Edit #2: I just installed an earlier version of GUIMiner and it's working now it looks like.