As mentioned on alt.steinberg.cubase, there is one main reason for the timing hassle with the jv-1010: It seems that program changes make the device "think" for while. The solution for this is to reduce them to a minimum (i.e only once at the start of the song). With cubase this can be achieved by switching them of for each part (default behaviour is to send them at the beginning of each part) by selecting the part and then change the program/bank setting to "off".

Hope that helps,

Ulf.