phpMyBackupPro is store in the config.xxx.??? file in the include folder... This may be because your other install of WAMP left just files... or maybe you still have that on the PC. Check C:/Windows and C:/Windows/System32 for LIBMYSQL.DLL
Yeah, this is an error from the PEAR side.. We are also looking into it.. Everyone is experiencing it, not just from Uniform Server. Your best bet will be to go to their website and look for it there and download what you need.
If you install the main install of MySQL and you are trying to run Uniform Server, yes there will be a problem because of the LIBMYSQL.DLL file that will be created in the C:/System or System32 folder by the main install... We are working on fixing this problem also....