As previously mentioned,
returning the hub is probably the simplest solution.
These are steps I've taken when having issues with hubs and USB Block Erupters (UBE):If Windows:
---If BFG: unplug all usb devices. Uninstall and reinstall the silabs driver
http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx)
---If CG then unplug and replug the UBE and reinstall WinUSB drivers using zadig.exe. This process is outlined in the GETTING STARTED WITH USB ASICS section of this document
https://raw.github.com/ckolivas/cgminer/master/ASIC-READMEIn addition, if using Windows then devcon.exe and a vbscript (that I can provide but don't have access to at the moment) will clean up unused USB devices. This may just make me feel better versus actually doing anything but the list of unused devices from plugging/unplugging can get rather long.
Start with only one USB Block Erupter and test for stability for an hour.
Blast a fan on the UBE to rule out heat issues
Try a different computer
Try a different USB cable
Try different USB ports on the PC (I have seen weird issues with USB 3.0 ports with some hubs)
Try each port on the hub
Try a different power supply
Try a different miner or different version of your current miner
Check the UBE to USB port fit, sometimes there is wiggle that can cause disconnects or bad data transfer.
Personally I would not buy any more D-link hubs but plenty of people seem to have had good results.