Sorry it took me so long to see this.

I see what the problem is. The problem may be that the original code data was repeated 2 times.

Try this one and post back if it works. I hope it will but IRScrutiner fails to decode it.

0000 006D 000C 000C 0030 0010 0010 0030 0030 0010 0030 0010 0010 0030 0010 0030 0030 0010 0010 0030 0010 0030 0010 0030 0010 0030 0010 052F 0030 0010 0010 0030 0030 0010 0030 0010 0010 0030 0010 0030 0030 0010 0010 0030 0010 0030 0010 0030 0010 0030 0010 052F

If it works as I hope it will, it should move the volume up/down exactly 1 time.

I simply got rid of the 2nd part (bolded below) and decreased the count from 24 (0018) to 12 (000C)

0030 0010 0010 0030 0030 0010 0030 0010 0010 0030 0010 0030 0030 0010 0010 0030 0010 0030 0010 0030 0010 0030 0010 052F 0030 0010 0010 0030 0030 0010 0030 0010 0010 0030 0010 0030 0030 0010 0010 0030 0010 0030 0010 0030 0010 0030 0010 0D2F

Note that the original code we started with reports F12 protocol from IRScrutiner.
F12: {D=5,F=4,S=1}, beg=0, end=47, reps=1