Make your thread title and description useful!!
It's really pointless to post just a message saying GBPVR is broke!!.
At least if you're going to post that, say that GBPVR is broke in Live TV, or in Music Library. Try and give some indication in the title of what you were doing when the error occured.

Make sure your description gives as much information as you can about the problem, otherwise I'm likely to ignore your question.

Zip and attach your logs
The logs are found in c:\program files\devnz\gbpvr\logs directory (unless you installed to another place).
Unless I ask for a specific log, then I mean all the logs. (typing individual log file names is my pet peeve)
You need winzip or another zip program (windows explorer in XP right click and send to Compressed Folder") to zip up all the files that end with .log in that directory.
Then in your post you hit "Go advanced" in the forum, then you can attach files with the button "manage attachments".

Object Reference not set
This is probably the most common error. It's a general .Net error which can be caused by lots of different things. The most useful thing you can do is Zip and Attach your logs (see above).

Give a version number
Give the version number of the GBPVR you are running, v0.97.7, v0.96.12, etc

Plugins
One of the biggest problems results from plugins. Try removing them to a subdirectory and see if your problems still exist.
Also what might be helpful is to mention all of the plugins that you are running (with versions if known). This will certainly help any of the plugin developers if they see the thread.

Report back if it's solved
There are some support request where it's not clear if the problem is solved or still open. Everybody who is using the search for specific problems they have would want to know what to do and what solved the issues. A short post like "changed that, now problems are solved" is great. If you have done nothing (like only rebooted, restarted service) but the issues have stopped, that's helpfull info too if it solved your issues.