skullmonkey but the problem with the menu not returning to its place its still there.
Can you also add your ftp details in edit fields in order for us to take closer look as the above CSS suggested would make the menu positioning right while it is scrolled down and up however will cause hinderance in default stage so not a feasible solution
For reference, You can follow thread post (5 point) procedure.
Also, Kindly try and update to the latest version of GK News 2 i.e.3.2.3 as the same comes with new features, major updates/improvements and various bug fixes as you seem to have quite older version installed currently
Would suggest to take backup of your site before performing aforesaid steps, in case rollback required whilst facing any issues e.t.c