Hi
It could be that previously, if you exported manually you used the encoder video bit-rate set at a different value. Exporting a clip in wmv format with a lower value will produce a smaller file. As an example the same small clip exported to PC as a 1080p wmv file....
Bit rate set at 512 b/s (smallest value) gave an output wmv clip of 833 Kb.
Bit rate set at 16384 b/s (largest setting) gave an output wmv clip of 15.9 Mb.
The VP auto upload to youtube (if you used this) may have a different default bit-rate value to the previous versions, perhaps higher, but there isn't a setting to change it under the utube window.
It may be that the default value that you set under the Computer/Data tab are implemented when you subsequently output using the Upload utube/facebook/Flikr tab.
Nat