In a bit of a bind here. I have just created a new, totally standard custom object in my Spring'14 DE, and added three fields to it with no problem (lookup to contact, number, text). I assigned it a custom tab and everything checked out.
I opened Salesforce1 and was pleased to see the new tab in the left nav, I can click through to it, see my records, click "New" - and successfully create a new record using the standard "New" page for this object (I haven't touched the page layout at all).
When I do create one and click save (which navigates me to the detail page) or I try to OPEN one of these records in Salesforce1, I just get this page:
The page you are trying to access is not supported on mobile devices
I'm very curious, I've been back over all the options, and I don't think I've missed anything, I totally believed that standard layouts for custom objects were absolutely supported on mobile devices?
Edit: I have now edited the page layout, and the changes reflected straight away on the iPad in the create/edit page, but I have the same problem on View.
Edit 2: I have cleared the cached data a bunch of times, and other changes to other bits of the org have reflected perfectly through this process.