Hi,
If you're using the Auctiva template builder, try using the image tags with URL in the tag name, e.g. [IMAGE1_URL]. Those generally will swap one for one as standard URL replacement with existing HTML code. Tags without the URL, like [IMAGE1], add alot of support code, like the supersize function.
There is a fairly good explanation of the tags on a sticky thread at the top of this section of the Forum.
Danno