Zoom problem + dimension & leader problem

[Mamma Jamma]

I searched for the answer, but grew impatient.
Acad 2007: I have a drawing that won't allow zooming IN beyond a certain level. Zooming out, no problem. While I've encountered issues with zooming out (resolved by changing/turning off limits, regen) I've never encountered an issue with trying to zoom in closer.
In the same drawing, and on a different note: the leaders are displaying only one grip and when attempting to stretch from any part, the whole leader moves. Same thing with linear dimensions. I can't find a variable to resolve this.
I don't believe the drawing was created or saved in a newer version, since the message "This drawing has been saved by a newer version..." never arose.

Any solutions to either issue would be greatly appreciated.

[jaberwok]

There is always a limit on how far you can zoom in but it's not often a problem because it's generally a long way in.
I assume you have Regenauto switched ON?

[irneb]

REGENAUTO doesn't help with the scroll zoom. Try REGEN when you hit that zoom-in "boundary". You'll probably then find that the zoom-out "boundary" has shrunk.

AC has this virtual screen on which it draws the entities. The "screen" is only so large, and (as an analogy) only has so many pixels ... so zooming closer than the 1 virtual pixel to 1 real pixel can't happen. Anything outside this "screen" can also not be displayed.

The regen rearranges this virtual screen so that your current zoom factor is about halfway between the min and max zooms. So once you reach one of the borders (sides / size) or the graining (pixelation) a regen can then "move" that limit away so you can continue zooming.