[Plugin: Google XML Sitemaps] Change XML Sitemap timestamp

Hello,
Possibly after I upgraded to wordpress 3.0, I’m seeing XML Sitemap build the sitemap according to UTC timezone adding +00:00 to the UTC timestamp which is some 5 1/2 hours behind where I am.
Previously I clearly remember that when I publish a post at say 5pm local time, the sitemap used to say, your sitemap was last successfully built on [date] at 5pm.
But now, it is showing some time which is 5 1/2 hours behind my local time.
The only change that I made to my site in the last few weeks is the upgradation to WP 3.0 (Could this be any reason?)
The time settings in the General page are set according to my local time but the sitemap doesn’t follow it.
I’m seeing slight decrease in traffic, possibly due to this, so is there any way to trick the plugin to use my timezone to build the sitemap (this was surely how it was before, but not any more)?