ok so the 3db does look like it might be down to the fact the cab got rebooted and I synced up before many crosstalkers.
I do have 2 lines, and both had firmware changed at the same time (obviously). What is odd is the max attainable on one of them which has jumped (line2).
Line 1 (which has G.INP enabled):
Before - Max: Upstream rate = 22806 Kbps, Downstream rate = 69544 Kbps
After - Max: Upstream rate = 25207 Kbps, Downstream rate = 69000 Kbps
Line 2 (no G.INP, and no interleave):
Before - Max: Upstream rate = 25040 Kbps, Downstream rate = 64550 Kbps
After - Max: Upstream rate = 25542 Kbps, Downstream rate = 75400 Kbps
Anyone know what the differemces are in the frimware/cards? I hope it's not increased the capacity in the cab - more crosstalk