Anyone else notice this?
Is your ad seasonal? Have you tried editing them and changing some of your keywords?
You can also try and disable the group and re-enable. Possibly a server is out of sync and doing this (while offering some downtime) may "re-seed" the servers.
good luck.
Our busiest day is usually Monday however yeaterday was more like a Sunday in terms of total visitors, the majority of who come through AdWords and regular Google search.