Several problems here and don't know if they are connected?

Totem Movieplayer will open requested utube video listings but when I try to play one of them I get the following error message:
An error occurred - location not found.

Resolution changed so that the refresh rate is only 60 (previously I could specify up to a refresh rate of up to 90). Resolution set at 1024 x768.

Had a screen flicker/colour fading problem so booted in safe mode, ran fix problems. This appeared to sort the flicker/colour fading.

The Totem error message is the most urgent for me at present, advise appreciated.

This morning I ran an ubuntu update.