Connection problem with X6 modem

I purchased a ZOOM X6 5590 ADSL wireless router modem to replace a Westell modem furnished by my DSL provider when it was fired by a lightning strike. I had to also replace a SMC wireless router. Since the strike took place on a Friday night it would have been the following Wednesday earliest to get a replacement from the phone company.
The ZOOM X6 had all the features combined in one unit and had a two year warranty.
It was very easy to configure. The wireless range is not as great as the SMC unit. My desktop computer located inside a cabinet on the second floor of the house had trouble connecting. The X6 is located in the basement. An external antenna fixed the problem.
After four days of flawless operation I noticed that I could not connect to the internet.
Checking the ADSL status on the X6 showed that it was connected (SHOWTIME).
Running the Diagnostic Test from the Advanced Setup menu stated that I had no problems. However the status light was blinking which according to the ZOOM documentation states that there was a problem with the physical layer.
I could not figure out a way to disconnect and re-connect the ADSL connection (reboot) so I turned the power off to the unit and turned it back on. Upon cold reboot the connection was re-established.
I contacted ZOOM and advised them of the problem. They suggested that I reset the modem to factory setting and then re-configure. I did that. Five days later the same problem occurred... This time I tried re-running the BASIC setup thinking that this is a way to do a hot reboot. It did not work. The ADSL status showed a connection (SHOWTIME) and the Diagnostic test showed everything working properly. The only way to re-establish a connection is to power down and power up the unit.
I again contacted ZOOM and told them the problem persists. They asked me my firmware version which was the latest (ver-2.0.3). They suggested that I return the unit for an exchange. Since the store is out of stock I wanted to keep the unit for a while longer. Five days later the same problem occurred.
At this point although all the other features are great I am going to return the unit for a refund since I don’t want to have to do a cold reboot every 4-5 days. ZOOM technical service response was great.
I have seen on other sites other people having similar connectivity problems so suspect it is not a faulty unit but a faulty design.