created an attachment (id=163354)
report

description:
in chart with two series in y-series, the tooltip always the same.

build number:2.6.0.v20100330-0630

steps to reproduce:
1. open attached chart.
2. select first series, move mouse over the expression, see average(row["creditilimit"]) tooltip.
3. select second series, tooltip still shows the same as step2

expected result:
tooltip reflect different series focus

current behavior:
always display the first focused series tooltip content
it seems chart builder does not reset tooltips for expression once series changes.
fixed. update the tooltip text when refreshing ui.
verified in 2.6.0.v20100414