global variable in code under test become NULL in PhpUnit

[toxic_brain]

hi,
I am pretty new to PhpUnit, started to write test cases for my classes.

I am getting NULL while i access global variables from my classes and it runs under PhpUnit. The code works fine when it runs under PHP.
tried workarounds found in websites , but no hope. 🙁

PhpUnit version is 3.2.15