FW K 1.22 and KPG-89D v1.60 are the last versions I have here. I've got K 1.21.00 in a radio that I use, and program it with KPG-89D v1.30 and v1.60. Note that the default bandwidth when adding a channel as of KPG-89D v1.60 is still, annoyingly, wide (it was dated 2009).
There is a KPG-89DN v1.61, released November 2012, that is likely narrow-band only (thus the "N" suffix).
If you load a radio up with a lot of zones/talkgroups/systems/freqs, near the memory and channel count limits, audit your changes carefully – there may be a bug that will lose or corrupt channels.