Following Maddog82’s suggestion earlier in this thread, I propped up the back of my N900 with an old cell phone battery that was lying around my desk and reconnected it. Since doing so about 24 hours ago, I’ve had zero cutoffs, and the throughput has been excellent. I’m wondering if overheating was the culprit, after all (even though another user on this forum has reported that his router malfunctions even though it’s in a cool room and apparently has good airflow; perhaps he has the version of this router that includes a hard drive).
With this apparent success, I decided to mount my N900 on some kind of stand. I failed to find a ready-made stand online, though I did discover the Dr. Cool, a dedicated router-cooler made by Evercool:
http://www.evercool.com.tw/categories/global/cooler/creativecooler/rc_01/dr_cool.html
The drawbacks of Dr. Cool are that (1) it cost $US 20-25; (2) some owners have reported fan failure; and (3) I’d have to wait maybe a week to get it. Further searching found a comment posted by a fellow victim called senzar226 on a June 2012 CNET review of the MyNet N900. He approached the overheating problem by attaching plastic feet to the bottom of the router.
Following his description, I got four plastic 1/2" end caps from the plumbing section of Lowe’s (26 cents US each) and a roll of double-side indoor mounting tape (about $3) from the same store. I mounted the caps as close as possible to each corner on the underside of the router, being careful not to cover up any of the air holes. The mounting tape, intended for attaching things to a wall, makes for a sturdy setup that keeps the router well off the surface of my desk. Also, the plastic end caps are made in such a way that they don’t seem to slip.
I was surprised (well, maybe not so surprised, really) that only a portion of the underside of the router is perforated for air flow. I think this router must need a lot more airflow.
Here’s a link to the page where you can read senzar226’s comment: http://reviews.cnet.com/routers/western-digital-my-net/4505-3319_7-35331596.html
NOTE: I have the router-only version of the MyNet N900, not the “Central” version with a hard drive. I’m sure that baby runs even hotter. Also, my router is a couple of months old, so it can’t be returned. I did write WD tech support a fews days back, but they haven’t responded beyond the automated “message received” confirmation.
I’ll monitor this workaround and report in a few days. Also, before reconnecting, I did a factory reset of the router and this time did not update the firmware, though I don’t know whether that matters.