Just wondering if anyone else has had similar problems with these.

I'm using Time Warner/Roadrunner in Southern California.  Up until
mid-February I was using a 3COM shark-fin cable modem. It worked great
for about 2 years; I think I may have had to reset it once during that
period, but otherwise it stayed running 24/7, giving me 2-3 mbps down &
384 kbps up.  I had nothing but good things to say about Time-Warner,
especially after reading some of the horror stories about providers like
Comcast.
That all ended when I woke up early one morning, noticed the internet
was down, and called their customer support number.  As it turned out
the outage was neighborhood-wide, not just something at my house, and
they had it running again by the time I got to work that morning.
Beaurocracies being what they are, a trouble ticket was generated anyway
for my account, since I was the first one in the neighborhood to report
the problem.  A few days later a technician comes by, work order in
hand, and replaces the 3COM with a RCA DCM315, as well as replacing the
cable drop outside the house.
Since then I've gone through 5 of the modems, and they've replaced the
cable drop yet again.  About twice a day, on the average, the modem will
disconnect, and then go through the whole Tuning-Ranging-Registering
process, taking anywhere from 10 minutes to 3 hours to get back online.
It seems worse during daylight hours, but maybe that's just my
imagination.
    I've got a few machines connected to it through a Linksys
BEFW11S4 router/switch, the same configuration that gave me no trouble
before the modem change.  I never have problems reaching 192.168.100.1
(the modems IP on my side).
Here are the signal levels, etc. when it's working:

----------------------------------
Cable Signal Details
Forward Path:                           Return Path:
Signal Acquired at 603.000 MHz          Connection: Acquired
SNR: 34.0 dB                            Frequency: 31.8 MHz
Received Signal Strength: 2.8 dBmV      Power Level: 50.0 dBmV
Micro-Reflections: 41 dBc               Channel ID: 4
Modulation: 256 QAM                     Modulation: QPSK
----------------------------------

And here's a typical cable modem event log:

----------------------------------
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol
timing    00:00:02 - 01/01/1970    22:22:53 - 04/10/2004    6993

SYNC Timing Synchronization failure - Failed to acquire FEC framing
00:00:03 - 01/01/1970    22:22:53 - 04/10/2004    2330

No Ranging Response received - T3 time-out    00:00:06 - 01/01/1970
22:39:15 - 04/10/2004    2455

SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame
within time-out period    00:00:08 - 01/01/1970    22:23:17 - 04/10/2004
594

Init RANGING Critical Ranging Request Retries exhausted    00:00:44 -
01/01/1970    22:39:06 - 04/10/2004    133

Started Unicast Maintenance Ranging - No Response received - T3 time-out
00:01:53 - 01/01/1970    22:41:54 - 04/10/2004    400

DHCP FAILED - Discover sent, no offer received    00:02:05 - 01/01/1970
00:03:46 - 01/01/1970    4

DHCP FAILED - Request sent, No response    00:02:32 - 01/01/1970    22:15:29
- 04/10/2004    4

DHCP WARNING - Non-critical field invalid in response.    00:02:33 -
01/01/1970    22:39:21 - 04/10/2004    9

Received Response to Broadcast Maintenance Request, But no Unicast
Maintenance opportunities received - T4 timeout    00:03:34 - 01/01/1970
22:37:30 - 04/10/2004    20

TLV-11 - Illegal Set operation failed    20:08:39 - 04/10/2004    22:39:24
- 04/10/2004    5

TFTP Failed - OUT OF ORDER packets    21:46:02 - 04/10/2004    21:46:02
- 04/10/2004    1
----------------------------------------

Many of the customer service people I've spoken to (at least those that
had any clue about how this stuff works) admit that these RCA modems
have been giving them trouble, but they're unable to do anything about
it because Corporate has decreed that only these will be used from now
on. (I'm guessing to make everything DOCSIS 2 compliant).
If I'm able to call them while it's down, they can detect that
something's amiss, but invariably when a technician finally arrives days
later everything's working fine, and all he has is a truck full of
DCM315's to swap out.