Just for an example, here's a CAMLquery I just set up:
CAMLQuery: "<Query><OrderBy><FieldRef Name='PublishDate' Ascending='FALSE'/></OrderBy>"+"<Where>"+"<And>"+"<IsNotNull><FieldRef Name='PromoImg' /></IsNotNull>"+"<Neq><FieldRef Name='PublishDate' /><Value Type='DateTime'>1900-01-01 00:00:00</Value></Neq>"+"</And>"+"</Where></Query>",
As you can see it's a bit more complex, but the formatting is basically the same as yours.
Can you try the GetListItems call without anything else wrapped around it except the document.ready()?
M.
p.s. I *always* work in SharePoint Designer, so I don't think that it's doing anything to you. I edited the CAMLQuery above in SPD2007.