Sound Studio + M-audio = No Input Levels?!, can't adjust input signal levels Options

[dickmanne]

Hi anyone. Hope there's an answer for this one:

Have digitized aout 100 vinyl LPs with great results using Felttip's Sound Studio.
Unfortunately the 1/8 inch audio input jack on my iMac was damaged and rendered inoperable.
Purchased M-Audio's Firewire Audiophile digital audio interface unit as an alternative to signal input at damaged jack. Modest signal achieved through firewire port but input level adjusters on Sound Studio's software user interface are grayed-out and unable to be used as before to tailor the levels. You can see them gray-out as the M-audio device finishes "booting" several seconds after turning it on.
Further, output adjustments on M-Audio unit to boost signal from receiver/preamp to computer produce no effect even though sliders move, etc.
Have checked all appropriate boxes, dotted all "i"s, crossed "t"s etc. numerous times on every available pull-down window or adjustment pane on the Mac and all software and still can't bring the signal up to appropriate recording levels.

Any advice is appreciated. I love hearing my old vinyl!!!