Free upgrades to the 3.1.1 version of Invig Classic and the 4.0.5 version of Invig PRO are available at the links at the bottom of this message.
4.0.5 fixes a number of problems dealing with opening old projects. It also fixes a problem with selecting Sets from the Sets Menu, occasionally failing motion blur, allows entry of more than 250 characters in the text window and enhances rendering of shadow planes.
4.0.5 also adds a helpful new feature where if materials or object styles have missing maps a little ? mark will appear on the swatch. This helps you locate the problem swatches and either fix them or delete them so you stop getting the message about the missing maps.
3.1.1 fixes a numer of problems dealing with reopening projects and has enhancements which increase stability.