Simply - avast does not make these changes to browsers, and avast never has a clue what POP mail client is being used and does not make any changes to them.
Oh yes it most certainly DOES!!! I just had the same thing happen to me.
Avast 4.8 Home
Win98SE
SeaMonkey 1.1.11
ZoneAlarm 5.1.033
Spybot (but not teatimer)
All except Avast have been working fine for just ages. Used to use AVG 7.5 but that is going to stop getting signature updates soon so I uninstalled that, rebooted, installed Avast, reboot, look through settings.... try to download some email and all my passwords are gone?
? Unlike edsacks, I was not doing anything with any USB devices to need any troubleshooting, and I did not do any avast uninstall so that is not the reason.
avast's interaction with browsers is limited to intercepting the http calls it makes at the network level and the same goes for the unsecured POP/SMTP calls of mail clients, again at the network level. avast knows nothing of the internal working of any given browser or mail client.
That may be true for the scanning process but the email setup wizard does indeed muck with your email profile. It presents a list of email accounts to select which ones should be screened and which should not, then demands that you pick a "default server" for both POP and SMTP. Now for those of us having multiple accounts from each of several providers, that seems a nonsensical request, but one must comply to finish the wizard. Anyway, it then does inconsistent changes to email profiles - some but not all of the selected accounts have their server settings changed to 127.0.0.1 as described in the help file. Unfortunately not all selected accounts at the "default" server get this treatment, and it is also applied to some but not all selected accounts at different providers that formerly had unrelated server settings.
I think that there is a probability during the changes you were making to get the USB drive installed SeaMonkey may have had difficulty getting to the stored profile information for your browser and email client and created a new clean profile.
As noted, I didn't have the USB drive issue, so that would be a red herring. SeaMonkey has no trouble finding my profile even now, it knows all my email accounts, or at least their names - it is the server settings and passwords that are mangled. No new profile was created, the wizard has changed the existing one.
1]
Avast does not deleted passwords nor a password file. Unless it is detected as being infected, but then it will notice you, unless you have told avast to automaticly delete infected files without asking. But in that case you can see in the log file that it has happened. Unless you disabled logging ofcourse which is not very likely.
This much seems to be true. The password file is still present in my profile,and the file contents even look similar to one of my old backups. I even tried temporarily replacing it with the backup copy but that does not restore access, so I put back the current one. There was no warning of it being infected or anything like that, and no mention of it in the log files. Nor did I turn off the logging or set automatic delete for infected files, the file is still present and it contents appear intact. Just not USEABLE. This makes me think there is something gone amuck when the wizard changed some part of the prefs.js file or similar.
3]
It is SSL(!), avast wil not do anything to/with it unless you manually configure avast for SSL connections (if already possible)
Not sure about this one, I think I had all those checkboxes marked anyway so can't really tell.
If you still need/want help, please provide more information like:
Errors? If so which ones and from wich application
No error messages. Just the problem that passwords are not accessible from SeaMonkey. Note this is ALL passwords - over a thousand of them - forum passwords, shopping sites, webmail, online banking, phone voicemail, bulletin boards, etc - not just the email ones. And yes, cookies too, though I only had a few dozen of those so not such a big deal.
Does e.g. Opera work fine?
What SSL settings? In what application, etc?
Don't know about Opera, never had it installed. I have not used anything else for browsing or email except prior versions of SeaMonkey (previously Mozilla, previously Netscape) since NS4.x days, so don't have other accounts to compare results to.
I expect there must be lots of SeaMonkey users hit by this, but not many postings. It becomes difficult to register for this forum to post about it when your email passwords are gone and you cannot retrieve the activation email!
So the next questions become:
What exactly did the wizard do to my profile? How can it be fixed? Would uninstalling Avast undo whatever it did since the password file itself seems intact? I need my passwords back a whole lot more than I need an antivirus program!!!