Linux can not properly identify file type

Linux can not properly identify file type

I'm using openSUSE12.3 now,and I've encountered a weird matter some days ago.
openSUSE is released with Libreoffice suit,and it works right.But I prefer
WPS,which is also an office suit like MS-Office.I installed WPS For
Linux,and found that my system could not identify XLS and PPT file
correctly.If I associate xls file with WPS Spreadsheet,ppt file would also
be associated,and vice versa.I checked
u~/.local/share/applications/mineapp.listv,and the related information
is listed below:
[Added Associations]
...ommited...
application/vnd.openxmlformats-officedocument.presentationml.presentation=wps-office-
wpp.desktop;
application/vnd.openxmlformats-officedocument.wordprocessingml.document=wps-office-
wps.desktop;
application/x-ole-storage=wps-office-wpp.desktop;
...ommited...
[Default Applications]
...ommited...
[Removed Associations]
application/x-ole-storage=wps-office-et.desktop;
I think that both of xls and ppt file are treated as
"application/x-ole-storage",so my WPS cannot specify them.I've tried to
unstall WPS and reinstall Libreoffice,but still cannot fix it.Does someone
have ideas?Thanks.