Windows Live Mail: Some errors occurred while processing the requested tasks. (0x80072726)

Hi,
I'm using Windows Live Mail desktop client (Version 2012 (Build 16.4.3508.0205)) on my Windows 8 Pro 64bits. I have several email accounts configured and it seems to be working correctly, except for this enigmatic error message:

Some errors occurred while processing the requested tasks.
Please review the list of errors below for more details.

But no error is actually specified. I have 8 mail accounts set and the error will always be associated with the last one on the list. It doesn't matter what is the last account, it will fail. (If I exclude it form the periodic checking, the new last one will fail). It doesn't actually fail because I receive the messages.

Also, this error happens every few minutes, meaning that WLMail is also not respecting the time interval I set for checking new messages (20 min).

I have two screenshots here: https://www.dropbox.com/sh/ug058uky7b3vkq5/Usle-sHFAC

Any ideas about what can be happening?

Thanks


EDIT: I found this in the log:

Mail:            Zone_MailChk ERROR: (httpauth.cpp:1112), failed with 0x80072726

It's the only error I see there and there are lots of it.