Problem with figures side by side

[Paul Smith]

Dear All

I am trying to insert two figures side by side in a document and I have 
followed the instructions indicated on:

http://wiki.lyx.org/pmwiki.php/FAQ/FiguresSideBySide

Unfortunately, the figures, although appearing side by side, are not 
vertically aligned with each other, I mean, the one on the right is 
placed bellow the other one. Is it possible to eliminate that vertical 
misalignment? Could somebody here please help me?

Thank you a lot in advance!

Paul