TGPGUILib was developed long before Vista was available and as it was created outside of Planetside, we do not provide official support for it. Since development on TG 0.9 has ceased, it is unlikely that the TGPGUILib will be updated if there is indeed a problem with it.
That being said Vista is generally compatible with most legacy software, so it may be a problem that can be worked around. If you can be more specific in describing your issue it may be possible to determine a solution.
- Oshyan