i want to know that is there any problem in calendar CSS because i changed some part of CSS but that effect in differing in mozilla firefox

is there any problem with MOZILLA FIREFOX
i am using richfaces 3.3.1(the latest)
or there is some problem in my CSS code
i am putting that part here below

.rich-calendar-holly {
 background: none;
 color: black;
 font-weight: bold;
}

.rich-calendar-cell {
 color: gray;
}

.rich-calendar-btn {
 color: black;
 font-weight: bold;
}

.rich-calendar-hover {
 background: #BBFAA9;
}

.rich-calendar-select {
 background: #B49FEA;
}

the below is my <rich:calendar> part in the page

<rich:calendar id="cal" datePattern="dd/MM/yyyy" required="true" showWeeksBar="false" currentDate="#{acessCalendar.selectedDate}"
isDayEnabled="callmyFunc" todayControlMode="hidden" inputStyle="width:80px" value="#{trainPojo.journeyDate}">
 <s:convertDateTime/>

<f:facet name="header">
 <h:panelGrid columns="3" width="100%">
 <h:outputText value="{previousMonthControl}"
 style="font-weight:bold; text-align:left;" />
 <h:outputText value="{currentMonthControl}"
 style="font-weight:bold; text-align:center" />
 <h:outputText value="{nextMonthControl}"
 style="font-weight:bold; text-align:right" />
 </h:panelGrid>
</f:facet>
</rich:calendar>

i am using these
i am getting the holiday(weekend part) part as transperent in mozilla firefox (any of verion from 3.0)(i have tried it in this versions )
i havent tried in CHROME or OPERA

please tell
am i missing something
in CSS part or