Have you tried System Restore to roll-back to before you lost this ability?

Mart

Did you lose ability on the icons in the upper right of the window or does
your cursor not turn to the "double-arrow" when you hover over the lower
right 'handle?'  If you do get the double-arrow, can you drag to resize the
window?
Sorry for all the questions, just trying to narrow down the symptoms......
                   Heirloom, old and overly detailed