Switch case-break changes checkbox.checked?

Hi,

It seems to me a very odd problem. In a switch case-break clause I declare a checkbox and it is checked to either true or false depending on an if clause. Then after the Rows.Add() row the checkbox changes, according to the debugger. Can "break" have these side effects?
cell.Controls.Add(checkBox);
tblRow.Cells.Add(cell);

tbl.Rows.Add(tblRow);

break;
...