Yes, it certainly will cause problems and it will not work at all. Your developer has been continualy ignoring PHP warnings that superglobals were deprecated and were going to be phased out in 5.4 There are very good security reasons for it and all over the web FOR YEARS have been posts to not use superglobals. Get him to fix it and cross your developer off your Xmas card list. It is easy to fix using session variables instead.
Post edited by John Chewter at 2015-04-08 08:55:54