The past few days I've been having lag with eve. With the storms here affecting the power & phone I thought it just was a problem of waiting it out.
The storms passed and I was still having problems. I ran chkdsk (the power problems caused my machine to randomly shutdown/reboot) and didn't find any issues.
Having recently installed SP1 I thought it might be related but the search engines didn't reveal any problems reported with Eve and SP1.
The lag appeared to focus around problems with using the market, docking/entering space & jumping between regions - using contracts, fitting & using the hanger was fine.
Using the market was weird - I would lag out for 1-2 mins and the market looked like it was doing a double refresh. Clicking on an item would hang the interface (I couldn't do anything else with the eve interface or even switch to the Windows desktop) - after a minute the information would appear and then it would hang for another minute and the information would refresh again.
I started to think it might be permissions related - related to something that had changed with installing SP1. I was starting to think about reinstalling Eve when I decide to move the CCP folder in User/<username>/AppData/Local to the desktop - so I could move the settings after a fresh install. Just to try, I ran Eve again - (without the settings so it would recreate the settings and hence fix any permissions problems) - and my issues disappeared.
I still have some investigating to do but it appears that it's either permissions or some part of the settings became corrupt.