I don't usually do it but I'm having a new problem. When I open a project all the clips are moving to timeline zero. They all shift to the far left. I think this started with the April update on my system. My work around is to lock all the clips once I have them in place, but it sucks because there's extra work to unlock them if I decide to bring in a section at a different time.

I often lock clips in place - I've had too many unfortunate accidents when stuff I didn't think was selected turns out to have been selected and I didn't notice until I'd done a bunch more stuff. It also stops me forgetting when experimenting which of a number of small clips have been moved where I think I want them and which still need arranging into the right place.

For me it's a kind of insurance, like autosave and versioning.

I never lock them and have never had a problem.

Hi. I never lock clips either, and do not have any problems with clips moving.
All the best.

This must be one of those "system specific" Sonar issues. I can find nothing about it in the docs so it seems to be a personal bug. Lucky me. 

yes

yes. in certain cases e.g. when manipulating tempo track and not wanting clips to move with it or when having completed editing a multi mic'd drum kit which I don't want to touch anymore (especially by mistake as with clip starts a few ticks before the measure this is really hard to verify if you have e.g. unintentionally group selected and nudged a tick or 2) ...
 
BTW - clips with locked data or locked position are excluded from ripple editing (they are locked afterall) so you might get surprising results if you don't think first what the consequences of both options at the same time will be (all seemed to work fine when gave this a try)

Yes. Mostly to save me from my own pilot error.
If I've done a boatload of edits on drums or vocals, etc...and I don't want to risk unintended selecting in some later editing session, it's cheap insurance.
 
 

Yes I lock them once I've edited them to my liking. I've accidently moved/deleted stuff too many times so I make it a point to lock them in position. I actually have one of the buttons on my Mackie Control setup to lock/unlock selected clips so it don't slow down my workflow (it's become a habit).