we use Oracle SQL Developer 3.2.20.09 with included JDK on Windows 7 32 bit.
When we open a sql file, in the Query Builder the criteria columns don't auto-adjust accordingly with the length of text present in the columns.
Also, if we modify or type a new criteria in a column, and immediately after drag the column header to widen the cell, the cell content is erased (if we click first in another cell the problem doesn't occur).
Please note that SQL Developer has included a Query Builder from a third-party since the 3.0 release. I will ping the developer that acts as liaison; perhaps you will get a more definitive response. I can only assume any UI bugs would have to be fixed by the third-party company at his request.