Description of problem:
A rule/row with 'Fact( fieldInt != null , fieldInt == 0 )' will give an 'Impossible match' warning.
A rule/row with 'Fact( fieldInt == 0 )' will also give an 'Impossible match' warning, if the cell for 'fieldInt != null' column is unchecked.

The two cases above are okay for String type fields (Integer/numerical type fields are affected).

A rule/row with 'Fact( fieldString == null , fieldString == "sth" )' should result in an 'Impossible match' warning, but doesn't. works on 7.3.1

The case above is okay for an Integer type field (String type fields are affected).

A rule/row with 'Fact( field != null )' or 'Fact( field == null )' and some action will give a 'Rule has no restrictions and will always fire' warning. works on 7.3.1

Version-Release number of selected component (if applicable):
6.2 ER1