Error msg receiving pop emails with Indy (sometimes)

I'm recieving pop3 emails via Indy pop3 component.   It works great except
about 1 in 30 messages, I get the following error:

Invalid Argument to date encode.
     then...
Unknown messages part type.

I have my email program keep going, but I don't get those emails.  If I go
into Outlook I get the message without any problem.

Thanks

EdB