I use Crazy Angel and haven't had any problems with it running so hopefully your new machine will solve the problem. Test it out on some couch roll until you're happy with the flow. Is it the TS20 machine you've got from Sienna? If so, try it at about "8 o'clock" to start with.
That's the one I've got. Although it has Crazy Angel's logo. I've had mine about 5 years and still going strong! (Watch out for a bit of seepage from the cable at the back though! - I sit the machine on couch roll)