You can hear horror stories from every registrar and many of the times the person who had the issues will call it deceitful tactics - even if it was a mistake.
My beef is with 1&1 - they renewed about 20 of my domains after I requested to cancel them, got the confirmation email, and click on the confirmation link. Within 2 weeks all of my domains were out of there.
I'm with GoDaddy and haven't had any issues with them (except the slow site and consistent pop-ups (go to domain manager - new window, go to this, new window etc..) and I also keep some at Moniker.