They work fine for me as well. I get files named uŠÔ‚r‚s’²¸i¶ƒf[ƒ^j.xls and Žó•t‚r‚s’²¸(¶ƒf[ƒ^j.xls, though. JWPce turns that into 瞬間ＳＴ調査（生データ）.xls and 受付ＳＴ調査(生データ）.xls .
If OpenOffice Calc doesn't like them, perhaps you should try uploading them to Google Docs? I would try to convert them, but each one contains a whole bunch of different pages and I'm not sure what the most efficient way to handle that is.
By the way, I thought LibreOffice was the new hotness.