Textbox Layout when Referencing

[Mick]

The situation is that when am using wordd 2007 final, I insert new drawing,
then a reference caption, enter my description, and a text box appears
containing this. Then in the document i select the textbox and enter a few
more lines of text as a description for a table. At which i notice it covers
the below text. Now if i click set text box porperties, then layout, then
inline, there is no change. My text box with added content still covers the
text below.

Clearly I could insert blank lines below the caption, but it becomes
annoying for many captions and is an unpleasent work around. Any ideas?

Thanks