bdurst08,
Unfortunately being unfamilar with Might Roms, I would be wrong to tell you that it would, there are alot of factors that play into this, such as:
1) What OS Build is in your phone?
2) What HTC Messaging Client Version/Build are you looking at?
3) CDMA or GSM version of the phone.
4) Is Arcsoft/HTC Messaging 2.1 (Older software) installed?
5) What has been altered in the registry?
My best answer to you is, make a backup of your phone or the one file your replacing the MUI and make the changes copy the MUI file, reset the phone and see.
And
aestivalisakito just confirmed my thoughts and previous statement without even knowing it! HTC Messaging Client is OS dependent to a point. Quote:
"
Latest Tp2 EXT Packages! Updated 6/15/10 - Also this has been adjusted to work with 21XXX winmo, if you have com 3 goto manila core app.reg and change "isCom3Project" and "Roamingicon" to DWORD:00000001. Remember to configure for your provider!
Link:
forum.xda-developers.com/showthread.php?t=700798