To getting rid of 404 error messages follow the step given below.

a. Launch the QUICKTIME PLAYER
b. Go to the EDIT pull down menu and select PREFERENCES
c. From PREFERENCES select QUICKTIME PREFERENCES
d. You will see a QUICKTIME SETTINGS WINDOW. In the window there will be another pull-down menu.
e. From the pull-down menu select STREAMING TRANSPORT
f. You'll then see two options: Choose UDP, RTSP Port ID 554

To changing QuickTime Connection Speed settings

Some movies are encoded to serve a variety of network speeds. To assure that you are receiving the proper stream type for your connection, follow these steps:

When the QuickTime plugin is open in the browser window, click the black arrow at the right edge of the controller bar as shown

When the Connection Speed window appears, select the appropriate speed from the dropdown menu.

NOTE: you may have to click the browser's Reload button to re-request the streamed file. These connection settings can also be changed in the QuickTime Player application (above instructions are to change them from the browser plugin); from the Player's Edit menu, choose Preferences and follow the step above for setting the Connection Speed.