I tried creating the file /etc/modprobe.d/dvb:

options em28xx card=45

But didn't get much further:

[  253.764174] usb 5-2: new high speed USB device using ehci_hcd and address 3
[  253.902125] usb 5-2: configuration #1 chosen from 1 choice
[  254.636109] Linux video capture interface: v2.00
[  254.683497] em28xx v4l2 driver version 0.1.0 loaded
[  254.685641] em28xx new video device (eb1a:2870): interface 0, class 255
[  254.685659] em28xx Doesn't have usb audio class
[  254.685664] em28xx #0: Alternate settings: 8
[  254.685669] em28xx #0: Alternate setting 0, max size= 0
[  254.685675] em28xx #0: Alternate setting 1, max size= 0
[  254.685680] em28xx #0: Alternate setting 2, max size= 1448
[  254.685686] em28xx #0: Alternate setting 3, max size= 2048
[  254.685692] em28xx #0: Alternate setting 4, max size= 2304
[  254.685697] em28xx #0: Alternate setting 5, max size= 2580
[  254.685702] em28xx #0: Alternate setting 6, max size= 2892
[  254.685708] em28xx #0: Alternate setting 7, max size= 3072
[  254.702068] em28xx #0: em28xx chip ID = 35
[  255.350113] em28xx #0: i2c eeprom 00: 1a eb 67 95 1a eb 70 28 c0 12 81 00 6a 22 00 00
[  255.350144] em28xx #0: i2c eeprom 10: 00 00 04 57 02 0d 00 00 00 00 00 00 00 00 00 00
[  255.350167] em28xx #0: i2c eeprom 20: 44 00 00 00 f0 10 02 00 00 00 00 00 5b 00 00 00
[  255.350190] em28xx #0: i2c eeprom 30: 00 00 20 40 20 80 02 20 01 01 00 00 8e 92 8f 46
[  255.350213] em28xx #0: i2c eeprom 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350235] em28xx #0: i2c eeprom 50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350257] em28xx #0: i2c eeprom 60: 00 00 00 00 00 00 00 00 00 00 22 03 55 00 53 00
[  255.350280] em28xx #0: i2c eeprom 70: 42 00 20 00 32 00 38 00 37 00 30 00 20 00 44 00
[  255.350302] em28xx #0: i2c eeprom 80: 65 00 76 00 69 00 63 00 65 00 00 00 00 00 00 00
[  255.350325] em28xx #0: i2c eeprom 90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350347] em28xx #0: i2c eeprom a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350369] em28xx #0: i2c eeprom b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350392] em28xx #0: i2c eeprom c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350414] em28xx #0: i2c eeprom d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350436] em28xx #0: i2c eeprom e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350458] em28xx #0: i2c eeprom f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  255.350483] EEPROM ID= 0x9567eb1a, hash = 0x12a535cf
[  255.350489] Vendor/Product ID= eb1a:2870
[  255.350493] No audio on board.
[  255.350496] 500mA max power
[  255.350501] Table at 0x04, strings=0x226a, 0x0000, 0x0000
[  255.350507] em28xx #0: 
[  255.350509] 
[  255.350514] em28xx #0: The support for this board weren't valid yet.
[  255.350520] em28xx #0: Please send a report of having this working
[  255.350526] em28xx #0: not to V4L mailing list (and/or to other addresses)
[  255.350529] 
[  255.936197] em28xx #0: V4L2 device registered as /dev/video0 and /dev/vbi0
[  255.938064] em28xx #0: Found Pinnacle PCTV DVB-T
[  255.958800] usbcore: registered new interface driver em28xx
[  256.148969] em28xx-audio.c: probing for em28x1 non standard usbaudio
[  256.148983] em28xx-audio.c: Copyright (C) 2006 Markus Rechberger
[  256.153490] Em28xx: Initialized (Em28xx Audio Extension) extension

Additionally modprobe em28xx-dvb didn't do anything

I think this is someone else reporting the problem a few months ago:

http://lists-archives.org/video4linux/24285-em28xx-and-pinnacle-pctv-usb-on-2-6-27-2-generic.html