Offset in selecting frames on the timeline My Dopesheet shows different frame to the one in timeline making such the whole project unsynced.

I noticed that when passing the frames in Dopesheet when I select frame 24 it jumps to frame 26, while timeline shows frame 25. At frame 50 it does the same thing. 

It goes accumulating, so when I get to frame 500, the difference is like 12 frames. Anyone experienced the same thing? I don't know how to get back to sync it again.
When number of frame which is selected in the Timeline / any of animation editors isn't the same as in the Current Frame value this means they are remapped to other values of Frames Per Second.
The unusual behaviour can be noticed even when clicking on frames in animation editors.



If this is not desired then change it back to default values for both Old mapping value and New mapping value (see manual about these options):


These values are 100 by default, but you can change it to any ones if they are the same.  


Can I increase the frame rate of an animation while keeping it the same length?.

How can I modify the frame rate without changing overall animation speed?.