Your data file has some problem!Possible reason: Certain VO tables produced by standard tools have
dangling ampersands in them, which is not allowed by XML.
Anyway, here is what R says:
Error in file(file, "rt") :
cannot open the connection to 'http://astrostatistics.psu.edu/MSMA/datasets/GlobClus_prop.dat'
Calls: loadData -> my.read.table -> read.table -> file