Hello Gizmox friends,
I upgraded from v6.4c to v6.4e. I did the cache cleaning and try to work on an existing project with a NavigationTab control. First when I tried to rebuild it, VS complained about the NavigationTabs.IsCollapsable property. Once I remarked it out from the concerned designer.vb, the project compiled and run without issue. However when I added a tab page to an existing NavigationTabs control through the disigner NavigationTab Collection Editor, the Desgin section (for properties Name, GeneratedMember & Modifier) on the right property pane for some of the existing tab pages disappeared. Clicking cancel button to close the editor and then go in again, I found that the added page disappeared and some of the existing pages appeared twice and the ordering got messed up too. Please verify if this is a bug. Thanks.
In fact the same problem was found for a brand new project. Just create a form with a NavigationTab control. Add three tab pages and run the application. Then add a fourth page and run the application and you will only see two pages instead of four.