Hi,
Unfortunatly this problem is with MSN and cannot be resolved by Messenger Plus! (I'm sure someone will be kind enough to respond with reasons why MSN are having this problem).
I can, however, totally agree with you on the fact they need to get this issue stabily resolved. I have (a few times) encounterred frustrating conversations with contacts due to message errors, i have even debated wether or not to totally change my messaging service. The only reason i havn't is due to most of my friends use MSN and would be a difficult task getting them all to migrate.
But yes, they need to resolve this issue and very soon.... and stable!!
Kind Regards,
XM4ST3RX