Chart is showing up as stacked bar instead of clustered,standard bar

[dumbell]

I need help understanding cognos behavior on this.
I even made sure there is enough space for the chart to expand. Still the 2 series (chartered as Y1 and Y2) in the chart are coming up as stacked instead of clustered.

Any help appreciated.

Dumbell

[dumbell]

Answering to my own post.

The query used for charting is a union product involved in MD relationship.
A substitute for this is:
                           Of the 2 series, take one series and plot it again.Make is transparent.
If interested, question and I can give details.

Not a common problem..