I think everyone suffers from bursts and lacks of inspiration.
I've got a number of ways that I deal with it. The first is simply to walk away for a while. I often find that after banging my head against a wall for a while on a post if I simply leave it for some time (be it minutes, hours or occasionally a day or so) and then come back to it I'm refreshed and can get something out.
The second is to search for something that inspires me. The internet is a wonderful place and with a little searching I can normally find something that gets my creative juices flowing be it a picture, a piece of music, a video or a piece of writing. I have several "stock" things that I go to depending on the scene and setting in question but there's a huge number of places where I can find new things be it as simple as a google search or looking at more specialised blogs/tumblrs.
The third, with regard to forum writing, is to talk to my partner. The reason the game started is that my muse fired when discussing it with them in the first place; if I'm struggling then I hope I can get it firing again. The best games generally come about when both partners inspire each other and good communication (which is always the key) means I'll hopefully be able to find my muse with them.
The fourth, if nothing else works, is simply to write anyway. It may not be efficient and it may not be good but just getting words on paper/a screen is a start. I may struggle, I may not write well but I've got myself a base for when my muse does come back and I at least have something to fall back on.