i finally understand the problem. please fix this.

1. "default Tab Groups" is always open
2. i open "work Tab Groups" that have 10 tabs in new window
3. i reload and check 3 of "work Tab Groups" and don't check the others
4. and i close the "work Tab Groups" window
5. when i open "work Tab Groups" window again, only the 3 tab that i checked last time, have links. the other 7 tabs, are null and when i click on them, it opens a blank page!