Current only confirmed fix is here: http://androidforums.com/evo-v-4g-all-things-root/595109-fix-everything-turning-your-phone-into-evo-3d-thread.html. It's your best bet. Old OP: There is an OTA available from HTC. Not much luck is being had with it, but it's something to try first. WARNING: IF YOU INSTALL AN OTA ON AN S-OFF AND/OR BOOTLOADER-UNLOCKED DEVICE YOU COULD BRICK YOUR DEVICE. TO BE SAFE, RELOCK YOUR BOOTLOADER AND RUN THE STOCK RUU AS INSTRUCTED IN THE UNROOT GUIDE BEFORE ATTEMPTING THE BELOW INSTRUCTIONS FOR THIS OTA UPDATE. Check for software updates first, then update your PRL, then update your profile. Try it for a while and see if this fixes the texting issue. Some say it's better at least, but it may not completely fix it. My old solution is under the following quote from this thread. EDIT: people are saying this isn't fixing their issue, but you should still apply the OTA when you can anyway. Older OP: I've had this problem for the entire time I've owned this phone up until now. Here's how I fixed it. I can't believe VM doesn't tell you to do this, but apparently it's in the manual somewhere. You're supposed to do this right after you activate online or swap online. EDIT: when you swap phones online and/or do this fix, make absolutely sure your old VM phone or phones are OFF and the batteries are REMOVED just as a precaution. 1. Start the Phone app. 2. Enter "##25327#" (this is ##CLEAR#) 3. The EPST menu should come up. Tap on Menu, then tap Reset 4. Tap on OK on the popup 5. Your phone will reboot, reactivate itself, and update its PRL. Then your SMS bug *should* be gone. This is the ONLY fix I've found yet to be seemingly helpful in fixing the extremely common Cause Code 64 Class 2 bug when sending text messages. Unfortunately, it hasn't been completely successful for most people. In the event this does not help you, please do the following: email firstname.lastname@example.org as well as calling their Executive Resolution Team at 877-291-5717 and tell them about the error and when it happens. The more people who do this, the better. Let's continue using this thread to tell people to contact VM about this issue so it gets resolved faster.