The problem is not likely your HDD.
I've never used the Boss unit you have, but it would appear that just as with all the VS units with burners and the external scsi burners, you eventually run into the failed burn problem.
Two things come to mind immediately that you can try without costing much:
1- get a cd/dvd cleaner disc and run it once, twice, three times, if needed.
2- If you have the convenience to do so, run down to a local supplier and try two or three different brands of blank cds. It is not uncommon at all for the VS recorders to have fits over CDs from time to time. I suspect the same to be true of your BR.
Don't bother with cds branded as "Music" discs, especially if they cost more than the run-of-the-mill data discs. My personal experience with them on a VS machine or two has never been good, where data discs have worked fine.
3- If you know how to do so and are confident of your skills, you could probably figure out how to remove and clean the CD drive by hand - very carefully so as to not put the laser assembly out of alignment, or otherwise damage the unit.
I'm almost 100% that it's not your hard drive.
I suppose you could always try making a copy of your Song and try burning it from the copy, or try optimizing it and then burning a disc.... or you could run a drive check to search for errors that might be causing the cd write to read erroneous info. These ideas are assuming you have such features on your BR. As I said, I am unfamiliar with it, but that's what we do with our Vs recorders.
Hope that is helpful.