Hmm, I remember after unpacking the pslaunch update manually, and calling pslaunch, I was notified of another update, which exchanged the serverlist.xml file. Possible that your manual editing disabled that. But you could rename your serverlist.xml (e.g. to serverlist.bak), so it doesn't exist anymore under the original name, then pslaunch might recognise it as missing (at least in a repair update) and revert it with the latest version.
The pslaunch update and the serverlist update were different updates though.
And the "wrong MD5 checksums" message was an error in the old pslaunch version (miscalculating them, never getting correct ones in this specific situation) - according to Xordan.