I've experianced this on two diffrent computers now. intellisense in vs 2013 fails to show without pressing ctrl space to make it popup. For things like seeing what parameters are required in a constructor I can never see any intellisense.
It is pretty anoying and im not sure how to fix it. On the first computer I was running win 8.1 preview, resharper 8 and vs 2013 preview. I am now running windows 8.1 RTM, VS 2013 RC, resharper has not been installed. Exact same issue.
Some examples...
Type some code press period to call a method or something and when intellisense would normally popup and tell me what the objects members are available nothing happens until I press ctrl space.
Another scenario is creating a new object lets say new myclass( at this point I would expect to see intellisense show me what parameters are available for the class, but instead nothing. ctrl space does nothing here.