Sitemap generator creating invalid urls

[Pepperama]

I am using version 1.4.2 and the the sitemap generator is creating the following URL on half of my product range;

http://www.albertmartincufflinks.com.auhttp://www.albertmartincufflinks.com.au/10-135-thickbox/superman-cufflinks-red-and-yellow-logo.jpg

The two errors are:
1) the domain name getting repeated twice
2) the "thickbox" term getting added into the URL.

I have pasted it in EXACTLY as it is appearing and Google will not accept the change / error.

Does anyone know what might be causing the error?