I finally got my M-Cell working again last night when I plugged it directly into the cable modem. I let it sit over night, and it was still working this morning. However, when I went back to the configuration I was using prior to Sunday -- when everything worked -- the constant 3G blinking light returned. The configuration that worked prior to Sunday was as follows: cable modem to DIR-655 Router, and DIR-655 router to M-Cell. Now that configuration no longer works.
So, that leaves me with the question of how, exactly, the DIR-655 should be set up for the M-Cell to work properly? As noted, it worked fine prior to Sunday with the current configuration, but won't work now when plugged into the DIR-655. I have tried the recommended configuration settings listed in the manual for the DIR-655 to no avail. So if anyone has any ideas, I'm all ears.
I have a DIR-655 and I noticed that I had IPS turned on and it was messing with the M-Cell so I just switched to priority mode configuration with the M-Cell. Just leave it with option C why do you want it the other way around?
I have had a variety of problems with this router. I finally gave up and went back to m trust old Linksys WRT54GS. Since then the MCell has been flawless. Additionally I see less other networking problems. I really think the issues with the DIR-655 started as of the last firmware update and I'm not the only one to notice that. I'm in the market for a new router now. I'm thinking a Linksys E3000 or E3200, or E4200. Or the E3000 and install tomato on it. My point is beware. This router is potentially problematic with MCell especially when you attempt port forwarding.