Version:           2.5 (using Devel) 
OS:                Linux

KDE 4.5RC1.

I disabled menu to free more space. On the next session startup I found that all konsole windows show rows/columns as 0/0:
{pts/3}% stty -a
speed 38400 baud; rows 0; columns 0; line = 0;

This causes applications to fall backup to TERM definitions which are mostly incorrect. Resizing window or enabling/disabling menu (which apparently has the same effect) correctly updates them. After show/hide menu:

{pts/3}% stty -a
speed 38400 baud; rows 40; columns 80; line = 0;

Reproducible: Always

Steps to Reproduce:
disable menu in konsole
start new konsole program

Actual Results:  
raws/columns of child terminal are set to 0/0

Expected Results:  
rows/columns of child terminal are set to actual window dimensions