We were comparing our SalesLogix Mobile Clients yesterday and one of our users could not see the Opportunities and History in his mobile client. I was running my client in IE8 and he was using Firefox 3.5. Without custom scripting there isn't anyway to hide the Opportunities or History in the mobile client. After reinstalling and redeploying failed I asked him to try another browser which immediately gave him back the Opportunities and History. So we now realized that FireFox was the cause, and after some time found our problem under Options in the Advanced section where offline data is managed. Here you have a couple options, first you can choose not to allow offline storage or you can exclude the Mobile Client web site. Now if you are missing your Opportunities and History you'll know what to do.