Update BOTH product code AND upgrade code for each version.
Else you can't re-install the new version without first uninstalling the old.

product codes:

1.2.1 max 8
ProductCode {1B495C25-655E-4519-B90D-5A0C71141C68}
UpgradeCode {F58F757C-5FCB-49BC-AD24-666AE428F30B}

1.2.1 max 9
ProductCode {8FE247D8-F552-4F17-B713-605A5A6312AD}
UpgradeCode {F58F757C-5FCB-49BC-AD24-666AE428F30B}

1.2.2 max 9
ProductCode {A55A712D-2AF1-4286-AA55-7C69512677D4}
UpgradeCode {F58F757C-5FCB-49BC-AD24-666AE428F30B}

1.3 max 9
ProductCode {FD3F22CB-8279-431D-8DA9-88FD5C3B259B}
UpgradeCode {F58F757C-5FCB-49BC-AD24-666AE428F30B}

1.3 max 2008 /32
ProductCode {57C71986-47F3-4397-B7BF-D2643F0CD38F}
UpgradeCode {F9BC584E-C0D5-4AEA-B6C1-6632B01B1572}

1.3 max 2009 /32
ProductCode {DA95D4B5-90C3-467F-ABBA-E620B528E205}
UpgradeCode {0F67380E-E35A-45A7-A9FF-111DE60D3F03}

1.3.2-rc0 /32
ProductCode {801C9053-8EA5-467A-BC96-EF59214ADB8F}
UpgradeCode {43A81118-87FC-4AB8-A5BD-DFE5BEF52062}

1.3.3-rc0 /32
ProductCode {801C9053-8EA5-467A-BC96-EF59214ADB8F}
UpgradeCode {43A81118-87FC-4AB8-A5BD-DFE5BEF52063}

1.3.3 /32
ProductCode {801C9053-8EA5-467A-BC96-EF59214ADB90}
UpgradeCode {43A81118-87FC-4AB8-A5BD-DFE5BEF52064}

1.4.0 /32
ProductCode {801C9053-8EA5-467A-BC96-EF59214ADB91}
UpgradeCode {43A81118-87FC-4AB8-A5BD-DFE5BEF52065}

1.4.1 /32
ProductCode {D9E55E69-6DFB-45B7-B8C2-E53E643F795F}
UpgradeCode {43A81118-87FC-4AB8-A5BD-DFE5BEF52066}