We also saw similar problems when translating DC designs into Dx, with pin names, net names and even components themselves (particularly Resistors) rotated in the translated designs.
The process of translating became so time consuming to "correct" the dx design after translation that we stops translating.
Now we have old designs based on DC and they will remain in DC - hence we have to keep a DC licence to enable updates whilst all our new designs are now based in Dx (version 7.9.1).
Only the plus side we are looking to move to VX from DX 7.9.1 as some point so if the translation problems are truely fixed then we may revisit moved our older DC designs to version VX.
This has been acknowledged by Mentor and a patch is being developed for the 7.9.5/7.9.5 releases to bring it into line with VX.1