Same issue in 1.4.4 -
43 tonne fuel rover on XL3 wheels docking either via a Clamp-o-Tron or an AGU/Klaw to an 18 tonne lander on 4xLT2's;
All testing done in Kerbin gravity; Docking typically breaks all 4 XL3's. If using Clamp-O-Tron the LT2's will also break at docking.
If using the Klaw, docking just breaks the wheels, and undocking results in a chain reaction of Rapid Unplanned Disassembly and a very Kerbal fireball as it appears the LT2's break and the fuel tank smashes against the pad.
I've also re-tested this with 6x LT2s on the lander. All 6 LT2's break, but this no longer results in a fireball.
This 6xLT2 Lander can otherwise survive a drop from 5.5m and it takes a drop of ~7m over the pad before it breaks all 6 legs.
