Adding attachments

Can't send mails with attachments. When a file is added to the mail and I hit the [Send] button, the attachments box disappear and the mail is locked (can't add the file again by clicking on the attachment button).
Read somewhere that some processes are slow. Did I not have enough patience?

I have noticed this when using Firefox 1.5 beta versions but not with 1.0.7 version.

Correct this is only a problem with FF 1.5, we are looking into it to see if we can fix it on our side. For the time just use firefox 1.0.* or IE.