It's unlikely to be a DLink problem but a PC issue. Dlink won't help you fix your PC and I can't comment further since nothing is told about the PC.
D-Link's DPH-50U works as advertised for most users but be warned that it does not work for all users. In my case the initial installation and setup went well and the device performed as expected. However later in the day my computer no longer recognized the device and I lost several of my usb connections concurrently. After some time the DPH-50U reports 'Device no Present' and shows the red 'not connected' icon in ones system tray.
In XP SP2, running devmgmt.msc shows 'unknown device' under Universal Serial Bus controllers. An internet search to solve this problem illuminated the fact that the D-Link DPH-50U is not a standard usb device. The installation software creates a unique usb setup which in my case has proven problematic. Those 'unknown device' entries were previously fully functioning usb devices; now belly-up.
The only solution I have found was discovered here:
D-Link must know of this situation as it has been previously reported; I discovered it by Googling D-Link "Device Not Recognized".
D-Link Support: None! I've phoned and emailed and have had one response. Here is that response:
Your Case ID is DLK397773915. What is the issue that you are having. I will take care of any of the issues that you are having with the DPH-50U.
My reply has been ignored and I have heard nothing further. What is the best method to proceed?