Some gadgets not saving certain fields after refreshing the page

Instructions for the Bamboo charts gadget

Steps:
1. Login to QA-JAC and add bamboo chart gadget hosted on JBAC.
2. In the preferences window, select the builds,select "Group By" as weekly,show builds from as "last 30 days" and refresh interval as "Every 30 mins". Save it.
3. It display the chart with desired build and group by weekly info.
4. Click to any other dashboard or any other menu of JIRA and back to the dashboard having bamboo gadget.

Result:
1. The chart is different, opening the preferences dialog show "Group By" and "Refresh Interval" is reset to default and not getting saved.

Expected:
1. The preferences for gadget should be saved.