Mac Excel javascript

When rendering a VF page as excel, it displays properly under windows, but under mac, the first cell looks like this:

if(!window.sfdcPage){window.sfdcPage = new ApexPage();} UserContext.initialize({"labelLastModified":"1335396211000","locale":"en_US","timeFormat":"h:mm a","today":"6/5/2012 10:12 AM","orgPreferences":[{"index":257,"name":"TabOrganizer","value":true}],"userPreferences":[{"index":112,"name":"HideInlineEditSplash","value":false},{"index":114,"name":"OverrideTaskSendNotification","value":false},{"index":115,"name":"DefaultTaskSendNotification","value":false},{"index":119,"name":"HideUserLayoutStdFieldInfo","value":false},{"index":116,"name":"HideRPPWarning","value":false},{"index":87,"name":"HideInlineSchedulingSplash","value":false},{"index":88,"name":"HideCRUCNotification","value":false},{"index":89,"name":"HideNewPLESplash","value":true},{"index":90,"name":"HideNewPLEWarnIE6","value":false},{"index":122,"name":"HideOverrideSharingMessage","value":false},{"index":91,"name":"HideProfileILEWarn","value":false},{"index":93,"name":"HideProfileElvVideo","value":false},{"index":97,"name":"ShowPicklistEditSplash","value":false},{"index":92,"name":"HideDataCategorySplash","value":false},{"index":128,"name":"ShowDealView","value":false},{"index":129,"name":"HideDealViewGuidedTour","value":false},{"index":132,"name":"HideKnowledgeFirstTimeSetupMsg","value":false},{"index":104,"name":"DefaultOffEntityPermsMsg","value":false},{"index":135,"name":"HideNewCsnSplash","value":true},{"index":101,"name":"HideBrowserWarning","value":false},{"index":139,"name":"HideDashboardBuilderGuidedTour","value":true},{"index":140,"name":"HideSchedulingGuidedTour","value":false},{"index":180,"name":"HideReportBuilderGuidedTour","value":true},{"index":183,"name":"HideAssociationQueueCallout","value":true},{"index":194,"name":"HideQTEBanner","value":false},{"index":193,"name":"HideChatterOnboardingSplash","value":false},{"index":195,"name":"HideSecondChatterOnboardingSplash","value":false},{"index":196,"name":"HideCSIGuidedTour","value":true},{"index":205,"name":"HideApexTestGuidedTour","value":false},{"index":206,"name":"HideSetupProfileHeaderTour","value":false},{"index":207,"name":"HideSetupProfileObjectsAndTabsTour","value":false},{"index":210,"name":"ShowContentUpdateAlert","value":false},{"index":213,"name":"DefaultOffArticleTypeEntityPermMsg","value":false},{"index":214,"name":"HideSelfInfluenceGetStarted","value":false},{"index":215,"name":"HideOtherInfluenceGetStarted","value":false},{"index":216,"name":"HideFeedToggleGuidedTour","value":true},{"index":268,"name":"HideChatterTab176GuidedTour","value":false},{"index":222,"name":"TouchExternalLinkReminderSuppression","value":false},{"index":224,"name":"HideUnifiedSearchGuidedTour","value":false},{"index":226,"name":"ShowDevContextMenu","value":true},{"index":227,"name":"HideWhatRecommenderForActivityQueues","value":false},{"index":228,"name":"HideLiveAgentFirstTimeSetupMsg","value":false},{"index":232,"name":"HideGroupAllowsGuestsMsgOnMemberWidget","value":false},{"index":233,"name":"HideGroupAllowsGuestsMsg","value":false},{"index":234,"name":"HideWhatAreGuestsMsg","value":false},{"index":235,"name":"HideNowAllowGuestsMsg","value":false},{"index":236,"name":"HideSocialAccountsAndContactsGuidedTour","value":true},{"index":237,"name":"HideAnalyticsHomeGuidedTour","value":true},{"index":238,"name":"ShowQuickCreateGuidedTour","value":false},{"index":245,"name":"HideFilePageGuidedTour","value":false},{"index":250,"name":"HideForecastingGuidedTour","value":true},{"index":242,"name":"TouchHideOptoutHover","value":false},{"index":251,"name":"HideBucketFieldGuide","value":false},{"index":263,"name":"HideSmartSearchCallOut","value":false},{"index":265,"name":"HideSocialProfilesKloutSplashScreen","value":false},{"index":269,"name":"HideGlobalHeaderSearchOptions","value":false}],"startOfWeek":"1","isAccessibleMode":false,"ampm":["AM","PM"],"renderMode":"RETRO","userId":"005U0000000Szd6","dateTimeFormat":"M/d/yyyy h:mm a","dateFormat":"M/d/yyyy","uiSkin":"Theme3","language":"en_US","siteUrlPrefix":""}); My Test Opp 1
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Here's the VF page that generates this:

<apex:page standardController="Opportunity" showHeader="false" extensions="OppContacts" contenttype="application/vnd.ms-excel#SalesPacket.xls" >
<style>
.fewerMore { display: none;}
</style>
    <apex:dataTable value="{! Opportunity}" var="opportunity" >
        <apex:column headerValue="Opp Name" value="{! opportunity.name}" />
        <apex:column headerValue="Owner Name" value="{! opportunity.owner.name}" />
        <apex:column headerValue="Account Name" value="{! opportunity.account.name}" />
        <apex:column headerValue="Billing Address" value="{! opportunity.account.billingstreet}" />

    </apex:dataTable>
<!--
    <apex:dataTable value="{!opportunity.OpportunityContactRoles}" var="OC">
-->
    <apex:dataTable value="{!ContRole}" var="OC">

        <apex:column headerValue="Contact Name" value="{!ContRole[OC].Contact.Name}" />
        <apex:column headerValue="Contact Phone" value="{!ContRole[OC].Contact.Phone}" />
        <apex:column headerValue="Contact Fax" value="{!ContRole[OC].Contact.Fax}" />
        <apex:column headerValue="Contact Email" value="{!ContRole[OC].Contact.Email}" />
        <apex:column headerValue="Contact Role" value="{!ContRole[OC].Role}" />

     </apex:dataTable>

</apex:page>