Unfortunately I have no all the sites where actually the xtremecarousel being used.
i think you need to call thumbs & picture with Classipress feature
cause i think is a damage to call them with Timthumb
who like you know was remove from Classipress from version 3.1.5 & 3.1.6
unfortunately i have not the time to deep inside
if i found solution (i talk loading and remove Timthumb) i will give you
over these is a good slider
Best of luck in your selling!!!!