Have you contacted Eset support? In my days as a consultant NOD32 always came on top for AV. Needless to say I have been using it myself without any issues. How do other games run? What NOD32 engine version are you using?
Have you tried other (seemingly unrelated) things such as graphics card updates, reinstalling NOD32? If you want to scan for spyware, give hitman pro a whirl. It will download a number of antimalware programs (Spybot and some others), run a scan with each and present you with a report. You could, for the laugh try the best version of their next software: http://www.eset.com/beta/ and not of there is any improvement.
LOL, for a start, counterspy is not anti-virus, its antimalware! Do you run any AV software now? Although there is crossover between these groups, there is no software package that offers comprehensive protection against both. Although Eset are working on it. If you found a significant speed improvement after removing NOD32, the your problem is elsewhere!
Right now, NOD32 + AVG's Antispyware (Previously ewido) is the most comprehenive coverage you can get. That said, using other free utilites such as hitman pro in conjunction with the two mentioned above is not a bad idea!