Yes TopText (eZula) can affect eBooksI am not sure about Surf+, but I suspect it can
KaZaa who distributes TopText is being sued by the Record companies, so this issue may go away in future
It is a serious issue, but I think it is more of an issue for ad-supported web sites.
My best suggestion for now, if you are worried about this issue is to provide information in your e-book on how to remove these programs including a link to various removal tools.
The best places to keep up to date on these programs are
www.geekvillage.com
www.ihelpyouservices.com
www.gethighforums.com
HTH