Could you try the following steps:
> Have both the textblock and the image on the page.
> Select the image.
> Edit > Cut.
> Double click the textblock to get it in edit mode.
> Place the cursor in the text where you want to insert the image.
> Edit > Paste.
> Select the image and then play with the settings in the Wrap panel.
PS: Do not move the image around manually - just use the Wrap panel settings.