That's strange. I can't spot the error in your code, but I am pretty sure something on your side is going wrong. I have put together a trivial demo with 2 listviews and 2 datasources, to demonstrate that this works:
http://www.wilcob.com:81/atlaswebsite/default.aspxIf you want, you can send me your exact repro and I could have a closer look at it. If you think that would help, send me your repro (including webservice) to wilco[ifyouknowwhatimean]wilcob.com.