Of course, the first thing I checked was my snap settings. I turned it on and off, and the slice still happened at the same spot every time.
The slice happened, for example, 1 second from the beginning of whatever clip I sliced. Every time no matter where the 'now' marker was.
Also, I pretty "O" to make sure I wasn't in offset-mode before I came on here. No luck.
I am 90% sure I restarted Sonar last night and the issue was still happening upon re-starting. Restarting Sonar is often on my list of 'fixes' for strange issues like this. Perhaps I should restart my system.
Hopefully when I open things up today the problem has 'solved itself'. Otherwise I'll slip edit my way around or something in order to get things done.
Thanks for your input everyone :)