My photogallery is a quiet big photo gallery with more than 400 categories and above 16000 images. I feel the admin panel options are very very very very very slow after the upgrade of latest version. To edit each and every album or image, it takes around 15 minutes of time. My site is running on a dedicated server with the below configuration:

xeon dualcore 1.8
ram 2gb
harddisk 160 gb
100 mbps connection

The issue happened only after upgrade to 1.6.1

i am using Apache 2.2 , php 5, and mysql 4.1 kindly help me to fix the problem or downgrade the version.