The only thing I have found so far is that all failing videos are played from address "http://encareenahdfi-vh.akamaihd.net/...". Videos from i.e. "'http://areenahdfi-vh.akamaihd.net/..." have no problems.
Edit: I entered "Ontto Kruunu"'s manifest to hdsdump and it showed that stream is encrypted with "Akamai DRM".
Edit: I entered "Ontto Kruunu"'s manifest to hdsdump and it showed that stream is encrypted with "Akamai DRM".