Solidworks Blocks blowing up

A little background: I’m creating a couple gearboxes for a class, so to make it easy to modify everything, I’ve placed the main sketch in a block which I import into each gearbox plate. This makes things easy to line up, and change, and all sorts of good stuff like that. I’m using Solidworks 2010-2011, education edition.

Unfortunately, sometimes when I change something in the block, some of the relationships in the sketches that include the blocks will randomly switch from, for example, the center of one circle to the center of another circle. As you can imagine, this breaks the sketch horribly, and takes a bit of work to fix each time. This takes a feature that is saving me quite a bit of time and making things easy to maintain, and makes it a lot harder to use.

Does anyone have any idea about what’s happening? From everything I know, I’m doing things right and this looks like a bug in Solidworks, but I can’t say that for certain, and even if it is a bug, I don’t know how to get it fixed. It’s easy to reproduce (unfortunately), so I can provide screenshots if that would help explain what’s happening. Or models.

Post screenshots. Depending on how you have your smart dimensions or sketch relations set up, sometimes the most logical result for solving them is not what you were expecting.

But it could also be a software “personality trait”. Use any software long enough and you’ll find conditions which the software doesn’t like very much. One thing I learned the hard way is that there is a limit to how many times you can mirror sketch entities before SolidWorks sets everything to over-defined with more red and yellow lines than you can shake a stick at. Most of the time merely deleting relations and/or smart relations and then re-adding them again fixes it.