I've searched the whole manual for everything to do with grid lines in the clips pane and all it basically says is that when this option is turned on (either behind clips or in front of clips) then they appear a measure apart in the clips pane. It does not say, however, that when you zoom in the resolution of these lines increases to a beat apart. 
 
This is with the Smart Grid turned off. With it turned on, the grid line resolution changes when you zoom in to match whatever snap resolution is automatically selected. But why doesn't the grid line resolution change to match the snap setting when the Smart Grid is turned off? I don't like to use the Smart Grid to be honest, but there are times when I'm zoomed in and set to a 16th note snap, and it would be helpful to have the grid lines match that - but the smallest resolution it does without Smart Grid is a beat. 
 
I can understand that when you're zoomed out with a snap of 16th notes or smaller, a matching grid line resolution is going to look a mess. But surely they could implement it so that zooming in without Smart Grid turned on would gradually increase the grid resolution up to a maximum of whatever you have the snap set to? Or is that a bad idea?  

I agree. If I don't want to use Smart Grid, and I turn it off, the grid lines should stay fixed to whatever the snap setting is set to.
 
There are many times I want to edit some audio and need to zoom way in. Let's say I want to edit to an 8th note grid and I zoom way in to get a good look. Now the grid lines, even with Smart Grid off, become 16th, 32nd, 64th, etc as I zoom in and it becomes difficult at times to even see which grid line I'm trying to edit to.
 
The grid lines should match the snap settings with Smart Grid off no matter how much you zoom in.
 
 
 

Workaround:
 
Set an audio track's edit filter to Audio Transients, right click the track and choose Pool > Add MBT to Pool. Then you'll get grid lines at snap resolution. but they don't re-draw immediately when you change resolution; you have to bump the timeline zoom.

brundlefly
Workaround:
 
Set an audio track's edit filter to Audio Transients, right click the track and choose Pool > Add MBT to Pool. Then you'll get grid lines at snap resolution. but they don't re-draw immediately when you change resolution; you have to bump the timeline zoom.

Thanks. That works. But it would be so much easier if Smart Grid could just be turned off and the grid displayed at the snap setting.
 

Totally agree, sharke.  But I also use Dave's workaround.  Found it unintentionally when learning Audio Snap.  It's pretty cool, I guess.  The thing I don't like about it though is the beat markers in the Time Ruler.  They cover up the points on the ruler.  Just a minor nuisance.
 
Kind regards,
 
Living Room Rocker