I think I fixed it!
I was pretty sure that the issue was due to the enhanced messaging service (or lack thereof....). I searched for "enhanced messaging service ems garble" and one of results was this link:
http://csrc.nist.gov/groups/SNS/mobi...ools-final.pdf
I saw they had mentioned SIM cards there, and I remembered that my SIM is currently not installed so that data will work when I run Android on my TP2. I popped in my SIM card and asked my girlfriend to send me a long text... and it worked!
However, I'm definitely curious as to why the problem started in the first place since my SIM card had been out for many months and I had not experienced the problem during that time....
Oh well... I'm just happy it works now! I do appreciate the responses from everybody.