When the web server's going through a flakey period (and after all, it is a Bank Holiday weekend coming up, so it's kinda traditional) it is actually the by-GPS entries that are most likely to fall through the cracks. This is because whilst data (such as a normal event entry) is backed up to a 2nd server instantly, the files structure including any uploaded files is only synched once per day.
We will publish the address for the 2nd server if things get bad over the weekend.