Google Spreadsheet Import Range #REF! Error (Randomly)

Question

This problem has been persistent for a while, just happens every so often at random times, nothing changing. I also do not know how to reproduce the problem, but I'll give a detailed explanation of what's happening.

Normally the importRange function works just fine, and looks something like the following:

The Spreadsheet key is typed correctly - I've been using this strategy in Google Spreadsheets for a while now.

Every so often, Google Spreadsheets seems to break down, or at least the importRange function does... and produces something like the following:

Google seemed to be freezing up at times today, which is when this happened. I've tried adjusting the importRange parameters to !X1:X, !X2:X5, changing the title of the Sheet that is being imported, etc.

In the past, changing from !X:X to !X1:X fixed some columns, but not always all of them. The only fool-proof solution to fixing this, that I have found, is recreating both spreadsheets. As the back-end (the one being imported) eventually becomes a report, I would like to spare my boss the extra effort of referencing multiple spreadsheets, and would rather just fix this and be done with it.

Does anyone know the potential cause of this glitch? Sometimes it fixes itself, sometimes it doesn't. It happens randomly, and only to certain spreadsheets (I have a set of 8 or so that all use importRange, and no more than 2 are ever affected at the same time). So I honestly have no clue where this is coming from.

Side note: Google in general has been a bit unresponsive today in terms of all its services - my university's App Engine email service was down for about half an hour. Could a limitation on resources/network attackers be causing this kind of behavior in Spreadsheets?

Update: I attempted to import to the same Spreadsheet data from a different Spreadsheet (i.e., gave the importRange function a different Spreadsheet key). Though the key and range are valid if imported into a different Spreadsheet, in my original (the one full of #REF!), that range is not imported correctly. This leads me to believe that this glitch may apply only to a single Spreadsheet, where any attempt to importRange from any other source is not functional.

Answer 1

This is a little late, but I came across it in a search so it might help someone else - try something like this:

=IFERROR(ImportRange(SpreadSheet_GUID,"Bookings!P:P"), 
 IFERROR(ImportRange(SpreadSheet_GUID,"Bookings!P:p"), 
 IFERROR(ImportRange(SpreadSheet_GUID,"Bookings!p:P"), 
         ImportRange(SpreadSheet_GUID,"Bookings!p:p"))))

Basically the idea is to force Google to recalc using variations of the original address (upper/lower case column letters).