Sorry I didn't check back on this last night. Any ways, the CDWriterXP.ocx file should already be in your BIAB folder. Also in the RealBand folder if you have that. First check and see if it's there, because if it is, that probably means miniburn isn't finding it. Try copying and pasting to windows\system32 and see if that works.
If it isn't there you can download it here (among other places) http://www.nodevice.com/dll/download.html#body
(you don't have to run scans or anything--just type in the letters and numbers and hit download--wait 30 seconds and download)

Also, you're right, there are several freeware/donationware apps for download. I use ImgBurn. You can check it out here: http://www.imgburn.com/

Hope this helps, and have a great day.

Jim