If both Multisite and Travel demo modules are installed the fallback site definition is extending the travel site definition. So any "siteless" request is then using travel site in the end. That causes at least one nasty issue, any site-independent page template is unusable by default.
There are of course some workarounds:

• make the template available under fallback directly
• extends override templates under fallback

But we still support the concept of freemarker and jsp page render types so this should not be necessary and in the end fallback site definition should not rely on any other site definition.