Avast blocking access to remote login site

About 2 weeks ago, I helped a neighbor clean up his old Dell XP desktop. I was shocked to discover that it had no AV or AS on it, and it took me a couple of days to remove 154 tracking cookies and trojans using Malwarebytes, SuperAntiSpyware, and ESET online scanner. I also installed Avast! and ran a boot scan, which, of course, removed some of the nasties. There is now no indication that the computer is infected (doesn’t mean there are none, but the computer now seems to run perfectly).

The neighbor works for J. P. Morgan Chase. This morning he informed me that since my cleanup, he has not been able to log onto his messages at JPMorgan.com. He contacted the JPM help desk, and they blamed Avast!; said it must be blocking access to the site. I have given him instructions to disable the shields for 10 minutes, then try to log on to confirm or deny that Avast! is the problem. If he’s able to log in with Avast! disabled, I gave him instructions to enter http://jpmorgan.com as an exclusion in the Web Shield, then turn the shields back on and again try the login. If he’s able to, problem will be solved. If he’s not able to, is there anything else I need to consider doing to make sure Avast! does not block the site?

Update definitions please