Yeah... CD Wave only reads 44.1 files. Remember, it's purpose is to split wave files at perfect CD sector boundaries.
<huh?>
data on a cd is split up into chunks, each containing 1/75th of a second of music. If you don't split your wave file right on that mark, your burning software must fill the gap with zeroes. This is what causes the little glitches you get if you don't cut them right on the cd sector boundaries.
<end huh?>
Anyways, all that to say CD Wave was designed specifically for makin' CDs so it doesn't accept a 48k file. It will rewrite the header for you if you want - but that will change the pitch and duration of your music.
If you just like CD Wave for cutting tracks, then you can still use it. When you're done you'll have to change the headers back on all the files. Or maybe you can use the cuesheet with the original file? If you're just trying to burn a CD, convert it to 44.1 with something good.