D717s and DLink switch compatibility?

Good afternoon, all!

We have a number of D717 desk phones and some M100 wireless phones in our customer's facilities. We're running into a problem where phones attached to D-Link DGS-3130 and DGS-3630 switches are behaving very erratically. In one case, a D717 stopped registering with the hosted PBX.  After some troubleshooting we factory reset the phone. The phone registered with the PBX, rebooted on its own, and took a DHCP address from the client VLAN rather than the VoIP VLAN. The unit had been working ine for months. 

In another instance, a group of M-100 wireless phones similarly broke down. Our vendor replaced them with another brand, which did not work, either. Only be replacing with a desk phone (D717) did the problem go away.

I've gone over the switch configurations and had no success in determining any issue with the switches. Before I start in on the PBX itself, is there any known issue between snom phones and DLink enterprise switches?

Thanks to all for looking!