Second, today everything was humming along and at the end of my work day I checked my account and it sowed last share 7 hours ago. I don't think I had made any contribution during this time. However my GUIMiner was clicking just normal showing 352 MH/S - In statistics, I have no shares from 19195 to 19199 while GUIMiner seem to be running normal. So I'd also like to find out what happened here?
I had this same problem today. One of Slush's servers is having connection problems or something (i'm not sure) but basically whenever I connect to stratum.bitcoin.cz it fails, but someone else posted some slush IP's and the one that currently works is 54.215.3.101
so in GUIminer i set that as my host, stop and restart, and then it started accepting shares and they were being credited to my account (where as before guiminer would generate shares but i received no credit)