Running 2012 WebAccess build 99876 (the internal build with the Time Zone fix) and a few of my users have alerted me to a problem attaching files in Web Access:

Say you have files "A" "B" and "C" and you compose an email and attach those three files in that order - in the compose window they will show as all three files being attached with the correct sizes. When you send the message the recipient will only get the last file you attached ("C"). Looking at the sent item just created will confirm that the other two attachments disappeared.

I've been able to reproduce this behavior in IE and Chrome on Windows 7. Anyone else seen this behavior?