I gave up on this issue for a while but have come back to it. Whilst updating the website on my test server I am still unable to submit pireps, they simply do not appear in the database despite there being no errors (except for the strict standards errors which I have turned off reporting). There appears to be no issues with the database and the website runs fine on the test server except for the filing of pireps (either manually or with acars).
I know that the database is being written to because I can add new pilots, add comments to pireps, delete pilots, etc. Any help is greatly appreciated.
On the current server I am running Win 2008 R2 with IIS 6.1 and PHP 5.3.19 (Everything works fine)
On test server I have tried both Win 2012 R2 and Win 8.1 with IIS 8 and tried PHP 5.3.19, 5.3.28 and 5.6 (full copy of the website and database, everything works apart from the submission of pireps to the database).