I think I found the answer to my question. Sharing it here in case anyone else comes across this.
"Alternate streams [ADS's] are not listed in Windows Explorer, and their size is not included in the file's size. It sounds like my RecordNow CD software *is* counting the size of alternate data stream(s) associated with the file".
Here is a little reading on it. Scroll down to ADS Alternate Data Streams