Yes, the PW3 will connect to calibre 1.48 -- however, the thumbnails that calibre creates were bumped in size for the Voyage, and that might be necessary for the resolution of the PW3 as well.
That only affects the cover view thumbnails though, and only the ones calibre sideloads.
N.B. -- there is a
sticky describing various options for calibre on WinXP. e.g. your computer will probably run linux quite well.
Running an outdated OS is not the best policy, security-wise