How can fix HDMI HDTV overscan when I my TV has no aspect ratio setting?

I have a 32" Vizio HDTV. It's a few years old, but running well. I just connected a new nettop to it using HDMI out. It's the Intel 3x00 graphics chipset.

I'm seeing overscan, where the resolution in Ubuntu is set to 1280x720, but the TV itself is 1366x768. When I go into the Monitors control applet, I cannot change the resolution to anything other than the current or 640x480.

A user had a similar overscan problem, but fixed the overscan by adjusting his TV's aspect ratio settings. I do not have that luxury.

Is there a way I can do this without having to delve into xorg.conf or other command-line craziness? I'm more than comfortable doing so, but there must be a cleaner way.

I'm running Ubuntu Natty, keeping up with updates and such.

Here's the output of lspci:

colin@bricktop:~$ lspci
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 12)
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
00:04.0 Signal processing controller: Intel Corporation Core Processor Thermal Management Controller (rev 12)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:1a.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 06)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06)
00:1d.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a6)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 06)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 06)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 06)
01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
02:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03)
03:00.0 Network controller: Atheros Communications Inc. AR9287 Wireless Network Adapter (PCI-Express) (rev 01)