hi krileon,
i did a fresh test.
On a temp site, installed the latest joomla 2.5.1 , CB 1.8 and used joomla default template (tested both atom and beez). Then created a simple checkbox field.
The problem still exists. The checkbox and the value are out of place. So it is not a third party template problem.
Another finding - At the backend field mgt, when I select row = 2, the PROBLEM is SOLVED ie. the checkbox and value are perfectly aligned. But the field description icon appears in the next line.
This suggests that the issue could very well be with CB afterall.