This can happen when crosstalk borks up one of the V4 figure's eye dials in a scene. The easiest fix to tell you is to restart Poser. Also, it wouldn't be a bad idea to reinitialize V4.

If you're having this problem exactly as you describe above, with the default V4 figure, then you really need to close Poser and initialize the figure using the accompanying bat file. If you can't find a quicklink to it that should have been installed with your product, you can find the bat file in your Poser's runtime directory, where you installed V4. ie: ......RuntimeRuntimelibraries!DAZDzCreateExPFiles-V4.bat

Running that should take care of the issue. Then, restart Poser and test.