are you using wdm drivers? i got a delta 66 with the omni i/o break out box and the latest drivers allegedly having wdm support...can't get it to work...though if i disable wdm in can get sonar to playback and record with the delta....the pre amps on the omni rock....
if ya gots the time: what processor are you using, how many track, plug ins, etc?
i haven't had sonar but a week and the delta for a day so i know that a lot of the problems i'm having are tweaking issues...however, i'm surprised i can't use the wdm with the delta....perhaps i installed the updated drivers wrong, or something got corrupted....i'll probably do a reformat and reinstall everything before i start writing to tech support.....
btw, i' m using windows ME....pIII 450 katmai chip...196 ram , 100mhz fsb.....sis620 chipset