Hi Jon
You said
It's probably just an incorrect setting at some point, but where.
When you burn/create a disc, the project has first to be converted to a mpeg file.
The size in Gb is determined by the length and the Bit Rate in Kbps.
A single layer disc holds 4.3Gb of data.
A top quality video uses 8000 kbps producing 4.3 Gb per hour.
VS 8 is probably using this setting.
If the length is 1 hr 48 minutes then the bit rate has to be reduced accordingly, to keep the Gb below 4.3.
A bit rate of 4000 kbps will allow 2 hours of video for 4.3 Gb.
Using a bit rate calculator may help in determining the rates
http://dvd-hq.info/Calculator.html (good reading anyway)
The bit rate can be changed in the ¡¥burner¡¦ module.
Click the options cogwheel, lower left and select Change Mpeg Settings.
I do not advise this approach,
much better to create a video file from the edit stage
To create a Mpeg video file of your project.
Go to Share- Create Video File.
Using the ¡¥Custom¡¦ option
Media Type DVD set the Bit Rate to 4000
Read my Guide below re:- bit rates and file sizes