Enter button not working to select dialogue in ep4 *spoilers*

[Lomo]

In episode 4 after Lee gets bitten I can choose whether to tell the others or not but after that my enter button won't let me choose any other dialogue options! Help please!
Def not my computer as enter button works on everything else

[Apache00]

Tried left mouse button to choose the options?

[Lomo]

Yeah that wasn't working either but after yet another re-start it is now working fine!

Bloody machines