i personally dont really run into this issue
usually even tho the phone is already set to it
i go into wireless and to home networks, and re select CDMA/EvDo even tho it should already be set to that
then i go into messages>settings, and open up and select ok on all the different message options, like text message length, multimedia message limit, sms limit
oh also turn on Split SMS messages
and then restart the phone, and i typically only see that people i send messages to may get them late, but they do get them