The factory data reset seems to clear up a lot of this sort of issue..

http://androidforums.com/htc-droid-eris/80233-factory-data-reset-option.html

 

The Market will know what you have paid for.

 

Reset absolutely did not help me with a lagging phone function. Did it last night and it actually seems worse.

 

I realize you're starting over with a reset, but if you've used the device heavily since the upgrade and reset, have you gone into the menu > settings > applications > running services area to see what load may be taxing your phone?

Also, do you keep hundreds of old texts? emails?

Have the caches been emptied on your browser, Market and maps? in settings > applications > manage applications > (following computing for sizes) menu > sort by size.

These measures, done routinely, can put the snap back into laggy devices.

 

^I just did a factory reset last night. I saved no texts or emails on the phone itself. Battery is definitely better than it was with 1.5 but the 'Phone' function is laggier. I'm messing with some settings now, we'll see what happens.