Thunderbird windowing problem

[j-retired]

After upgrading to TB3, I now have a problem seeing the right-hand side of the window.  I can use ctrl +/- to alter text size, but the right hand side which should show "reply/forward/delete" etc is off the end of the window.
The only way I can get access is to move the whole window to the left - i.e. so it goes off-screen - and then stretch the right hand edge till I can see the required details. There is no slider bar on the bottom to allow me to do anything else.
This happens on 3 different machines. All Nvidia though - does that offer any possibilities?
I cannot find any way to sort this out.
Firefox, OO, etc still all behave normally.
Any inspirational ideas anyone?

j

[Rudge]

  I can't create the problem.

[j-retired]

At present I have a partial solution: raise the resolution to 1280x960 instead of 1024x768.
This does not remove the problem entirely - if the window is full screen all is well, but if not maximised the problem reappears.
Mind you, a new problem appears, with which the forum cannot help..... I could do with a bigger monitor!

j

(GEForce 6150SE nForce 430 is the video card according to PCLOS hardware check)