Problem in installing the comedilib-0.7.20

i was using the comedi-0.7.65 and comedilib-0.7.19 now i want to upgrade to comedi-0.7.66 and comdilib-0.7.20. During the installation comedi-0.7.66 is installed successfully but when i will try to install the comedilib-0.7.20 then  I m facing the problem, i got the error in compilation 
Error description is below
calib_yacc.y 235  Confilicting types for YYSTYPE
calib_yacc.h previous declaration of YYSTYPE
/usr/lib/bison.simple : 432 warning passing arg 1 of calib_yylex from incompatible pointer type

so for what reason i got this error? if anybody know then pls informe me.

Regards
Murtuza
iASYS Technologies
mdt_100_at_hotmail.com
iasys_at_vsnl.com