Cross Browser Design Issues

I love using upfront. I have more to learn, of course. But I am having an odd issue with cross browser design.

The differences are weird, because they are across two macs, both using Chrome, but one machine is slightly older than the other. I am pretty sure this is the same with other OS's and browsers.

I have flushed caches, on everything; and it looks good from the editor on both machines.

The differences are small, but I feel indicative of a larger problem perhaps.

This is what I want (don't judge me):[image pos="1"]

And the other image ( I can't seem to insert this one) is what I don't want.

Thanks again for your help