Getting around the limitation on a number of controls on SharePoint page
Apparently there is a limit on a number of controls you can have on a SharePoint page. By default, no more than 200 controls are allowed on the SharePoint page. Not sure, why this limitation is there, but it is. To get around this problem, you need to increase the MaxControls setting in your web.config file:
<SafeMode
MaxControls="200"
CallStack="false"
DirectFileDependencies="10"
TotalFileDependencies="50"
AllowPageLevelTrace="false">
<PageParserPaths>
</PageParserPaths>
</SafeMode>
In my case, I have MaxControls parameter set to 300.