First PDF is SLOW... like 30 times slower

Attached is a sample application with the same method and logic (just hardcoded variable values). If I run this in debug mode in VS2013, it runs the first PDF in about 5-6s and subsequent ones in about 3s. When I publish to an IIS server (tried on a Win 7, Win 2008r2 and Win 2012) the first execution time is about 30s and the latter ones are less than 2s.

Please advise ASAP.

Note: as requested the license file was remove, it should go in the Lib folder. Also, the pdf is generated in C:\temp which can be changed by updating the variable "tempFolder"