Hello Deb. On you first issues, any changes you make in a span tag only effects the text in that span tag pair. It is not a file wide setting. if there is not text betweent the <span> and </span> tag pair, then no changes will be made.
Closed caption text line number one.
This would not apply the text-align command to the text. The following would:
<span style=”text-align:right;”>Closed caption text line number one.</span>
We are looking at the second issue of the caption background box not displaying.