DeciusBrutus - There have been a number of posts like yours, including mine. When I see a post asking how much service loss is normal, my immediate response is - none. But sometimes there is.
In May/perhaps early JUne I experienced similar loss of signal, but it has not reoccurred recently. In early 2012 I was having similar problems with a 3800 RG. When it got worse, I called in, was tested & shipped a new 3801 which worked perfectly for a year.
So, my message is - it does happen & is annoying. If it gets worse, instead of better call in for a remote test.
*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.