I dug deeper, and found that google is having issues communicatig with your server, and it getting the following error:
We encountered an error trying to access your server at https://www.e-junkie.com/gc/ResponseHandler.php -- the error we got is org.apache.commons.httpclient.ConnectTimeoutException: The host did not accept the connection within timeout of 10000 ms
Most orders come through, but there are several since the 27th that returned this error repeatedly before going through (one has not gone through at all yet, although it's over 12 hours old) - but most other orders go through just fine. It has been doing this to one order every day (2 on the 30th) since January 27th.
Now the weird part is that on January 27th, the following error message was returned on about 60 orders as I was marking them as "shipped" within Google:
We encountered an error trying to access your server at https://www.e-junkie.com/gc/ResponseHandler.php -- the error we got is javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake
The errors at the top only started happening after this. I cannot find a single error before January 27th. All of the affected orders are normal, there are no payment issues, and there is nothing about them to differenciate them significantly from other orders, or that makes them stand out.