As Ralf said: all information regarding the FALSE ALERTS of Anti-Virus software are in this thread... best idea: read it from the very beginning and don't get irritated by all those posts made by people who didn't know what they were talking about.
summary:
The keypress.dll was reported by several anti-virus applications to contain a trojan, more accurate: a keylogger called PWS.Hooker.Trojan .
As anti-virus companies seem to share their virus-databases you can imagine that after one of the big anti-virus companies updated their databases, the others adopted the same algorithms and thus spread this issue. The keypress.dll file was mailed to several of them to clear whether it contains the virus, as no other indications could be found for the reported infection. One after another the companies verified that the alert given by their scanners was a false positive, meaning: there never was an infection.
In the meantime Ralf compiled a new client with version 2.0.32.60 that includes another .dll with different algorithms which basically do the same.
This version wasn't reported to be infected by any of the AV-scanners and was created only "in case" there was an infection (to hit the 0.00001 % chance).
After updating your virus-definitions everything should work fine again, regardless whether you're using the old or new version of the 2.0.32.60 client, as both are CLEAN. If your scanner still tells you that there are infected files: get into contact with the seller of that anti-virus-software and tell them about the issue.
A huge amount of posts in this thread shows stupidity and arrogance of some unknowing, credulous users who couldn't keep their shirts on. It's ok if someone is concerned about security, but you really need to provide facts instead of accusing some project / software of containing viruses by mistake and thus basically ruining it.