First and foremost, a friend of mines got me hooked onto this game and I've been enjoying it thus far, however...

While doing the Item Drop Off Quest that has me backtrack to Arkor, I encountered a small bug where the entire event at the end of the Melanoid Mines repeats and the Chapter Number is set off by 1

Hmm I think this has been fixed (to my knowledge at least) because it didn't occur on my most recent playthrough. I'm long overdue for an update, though so it wouldn't surprise me if version 6.06 has this problem.

Thanks for letting me know and I'll double-check everything again.

I'm glad you found SU enjoyable! Let me know if you have any other concerns, or find any other bugs. Welcome. :)