The only way to get tech support is via these forums.
No mention of what the site is your trying to capture from? Debug logs contain no data - follow these instructions to capture debug logs for us. http://support.jaksta.com/discussions/topics/6000009063
Sounds like these mp3's are just false detections happening from other products such as your AV, browser updates or something similar. I know advast AV updates appear as possibly mp3's so will be detected if you don't switch the adblocker on.
You can see the content-types that will be detected and downloaded as mp3 by looking in your settings > internet downloads > Advanced > HTTP. Sort by the file extension column and look for mp3.
You can also look at the source url of the download by selecting one of these mp3's and right mouse clicking and selecting properties. This might give you and indication what the product is.
If it is a false detection from another product. You can add the url to the adblocker if its not already there - and switch the adblocker on. Settings > Internet Downloads > Advanced > Adblocker.
From CRS @ 19 Oct 2015 10:10