Okay...I did simple-scan -d and hit scan (it still said "Failed to Scan") and this was the output:
'Disable interpolation' type=bool size=4 cap=,soft-select,soft-detect
[+6.05s] DEBUG: scanner.vala:737: Description: When using high resolutions where the horizontal resolution is smaller than the vertical resolution this disables horizontal interpolation.
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (33)
[+6.05s] DEBUG: scanner.vala:734: Option 33: name='color-filter' title='Color filter' type=string size=6 values=["Red", "Green", "Blue"] cap=,soft-select,soft-detect
[+6.05s] DEBUG: scanner.vala:737: Description: When using gray or lineart this option selects the used color.
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (34)
[+6.05s] DEBUG: scanner.vala:734: Option 34: name='calibration-file' title='Calibration file' type=string size=4096 cap=,soft-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Specify the calibration file to use
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (35)
[+6.05s] DEBUG: scanner.vala:734: Option 35: name='(null)' title='Sensors' type=group size=0 cap=,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Scanner sensors and buttons
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (36)
[+6.05s] DEBUG: scanner.vala:734: Option 36: name='scan' title='Scan button' type=bool size=4 cap=,hard-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Scan button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (37)
[+6.05s] DEBUG: scanner.vala:734: Option 37: name='file' title='File button' type=bool size=4 cap=,hard-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: File button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (38)
[+6.05s] DEBUG: scanner.vala:734: Option 38: name='email' title='Email button' type=bool size=4 cap=,hard-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Email button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (39)
[+6.05s] DEBUG: scanner.vala:734: Option 39: name='copy' title='Copy button' type=bool size=4 cap=,hard-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Copy button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (40)
[+6.05s] DEBUG: scanner.vala:734: Option 40: name='page-loaded' title='Page loaded' type=bool size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: Page loaded
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (41)
[+6.05s] DEBUG: scanner.vala:734: Option 41: name='ocr' title='OCR button' type=bool size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: OCR button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (42)
[+6.05s] DEBUG: scanner.vala:734: Option 42: name='power' title='Power button' type=bool size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: Power button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (43)
[+6.05s] DEBUG: scanner.vala:734: Option 43: name='extra' title='Extra button' type=bool size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: Extra button
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (44)
[+6.05s] DEBUG: scanner.vala:734: Option 44: name='need-calibration' title='Need calibration' type=bool size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: The scanner needs calibration for the current settings
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (45)
[+6.05s] DEBUG: scanner.vala:734: Option 45: name='(null)' title='Buttons' type=group size=0 cap=,advanced
[+6.05s] DEBUG: scanner.vala:737: Description:
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (46)
[+6.05s] DEBUG: scanner.vala:734: Option 46: name='calibrate' title='Calibrate' type=button size=4 cap=,inactive
[+6.05s] DEBUG: scanner.vala:737: Description: Start calibration using special sheet
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (47)
[+6.05s] DEBUG: scanner.vala:734: Option 47: name='clear-calibration' title='Clear calibration' type=button size=0 cap=,soft-select,soft-detect,advanced
[+6.05s] DEBUG: scanner.vala:737: Description: Clear calibration cache
[+6.05s] DEBUG: scanner.vala:884: sane_get_option_descriptor (48)
[+6.05s] DEBUG: scanner.vala:895: SCAN_SOURCE not available, trying alternative "doc-source"
[+6.05s] DEBUG: scanner.vala:546: sane_control_option (2, SANE_ACTION_SET_VALUE, "Gray") -> (SANE_STATUS_GOOD, "Gray")
[+6.05s] DEBUG: scanner.vala:462: sane_control_option (6, SANE_ACTION_SET_VALUE, 150) -> (SANE_STATUS_GOOD, 150)
[+6.05s] DEBUG: scanner.vala:462: sane_control_option (5, SANE_ACTION_SET_VALUE, 2) -> (SANE_STATUS_GOOD,
[+6.05s] DEBUG: scanner.vala:530: sane_control_option (10, SANE_ACTION_SET_VALUE, option.range.max) -> (SANE_STATUS_GOOD)
[+6.05s] DEBUG: scanner.vala:530: sane_control_option (11, SANE_ACTION_SET_VALUE, option.range.max) -> (SANE_STATUS_GOOD)
[+11.22s] DEBUG: scanner.vala
sane_start (page=0, pass=0) -> SANE_STATUS_INVAL
[+11.22s] WARNING: scanner.vala
Unable to start device: Invalid argument
[+41.52s] DEBUG: scanner.vala:764: sane_cancel ()
[+47.08s] DEBUG: scanner.vala:767: sane_close ()
I can't make any sense out of this...I hope someone else can! Thanks.