A quick recap if you are new to Google Apps - this Google service can be used to host websites for free using the Google Page Creator module. Google web hosting gives you 100 MB of file storage space and undisclosed bandwidth.
If your Google Apps domain is xyz.com, the files you upload on Google Pages become available at xyz.com/[file name].
Now the big problem is that Google hosting service is not too reliable when used with Google Apps for your Domain.
There are frequent errors like Internal Server Error 5B, Error 503, 502 Server error, etc when trying to access pages hosted through Google apps.
The surprising part is that these webpages return server errors only when they are accessed directly using the domain address (like xyz.com/abc.html) - the problems disappear when we try to reach the page through Google pages control panel.
Unfortunately, the Google support pages do not offer any explanation of these cryptic 503 5B server errors though they occur so frequently.
I have been using Google Apps for a while now and am not too pleased with their hosting service. Similar issues have been echoed by other Google Apps users in the official Google Groups.
Think the situation would be no different for Google Apps premier customers who are promised 99.9% uptime for GMail but not for other Google Apps services.