Check the fuse connectors... The fuses may be just fine, but the connections may be poor.

I would disconnect the battery at the negative (-) terminal, and remove ALL the fuses. Using a wire brush (or even fine sandpaper), clean off all the fuse contacts. After you do this, pinch the connectors together a bit for a tighter connection. (Be careful not to pinch too tight). Replace ALL the fuses, don't put any of the old ones back in (just to make sure you keep any old corrosion out.) Reconnect the Battery.

If this doesn't work, check the wires hooking into the fuse block. Something might have come loose.

That's all I can think of right now...