My free minutes also did carry over this month. Still not showing sms balance. I have loaded GoSMS on my Defy and I see it has a message counter I can use in the meanwhile to track sms's sent. Just need to remember to reset it every 1st of the month.
Also have an issue that while making longer phone calls it drops the call. May be a Vodacom roaming issue...
For those having trouble with mms, a work around that may work, especially when roaming on Vodacom, is to change your APN in the mms settings from "mms' to "mobile.redbullmobile.co.za" It uses your bundle when you download mms's, but I find this the only way to send and recieve mms's for now.