5.2xLTS - Linux - Help search does not work with enter key

[ColeopterusMaximus]

Tested on Xubuntu 13.10 x64 - PB 5.21 & PB5.22 b2

When using the help window on Linux I try to search, if I type something on the search field and hit enter the search is not made

Changing the focus to the search button using the tab key and hitting enter works does not work either.

The only way for the search to work is to click with the mouse.

Note: This problem seems to affect mostly multi-monitor setups.