FCSW_Ben I am almost certain this used to work. So long as the beginning and ending frames of a selection were the same, they would wrap around the current timeline selection when Offset was enabled. Now, it only wraps at the edge of the animation in full.
Søren It's been a while since this was changed. Instead you can use Loop Start and Loop End to define the offset range. This was done to prevent having to box select since most offsetting takes place on the entire animation range.
FCSW_Ben Understood, I'll do that. It's a lot of extra work though, and I use this tool very frequently. The old behavior seemed sufficient, as a single click would choose the largest range possible for any set of keys.