Quests marked as Impossible when they are not

[grayseven]

As the title states, I have had a number of quests marked as impossible in the Cataclysm guide that are not. I have had to disable "Skip Impossible" in order to not blow past all these quests.

Is this an issue with the SIS?

[chaos5061]

Yes it is. Please disable the SIS function:
In these situations, we recommend that you right click the Z icon on the mini map, click the “+” symbol next to Zygor Guides Viewer, click Dynamic Progress uncheck all four boxes and move the slider to 80.

[Zygor Admin]

Please update to the latest version of the guide (1569) which disables SIS by default.