Thanks for reaching out to us here in our answers forum! I do apologize for any inconvenience you're experiencing when connecting to your Slingbox via the SlingPlayer for iPhone. I would advise uninstalling an dreinstalling the application itself and checking your iPhone for any updates it may have.
Here is an article from our support site which describes the uninstall/reinstall process:
Hope this helps!
The Sling Moderation Team