After the portsnap, Each terminal from the last session appears small, although I've changed the default size for new windows, and resized the existing small terminals.
I'm sorry, what is portsnap?
Portsnap is a FreeBSD command to update the port(software source) directories.
Ok, so does the terminal become small after restarting xfce or after running portsnap?
Yes. The ones saved from the previous session are small, and the default size of new windows is given in pixels, not characters.
This is weird. What version of xfce are you using? And what version of the terminal (if it's 0.8.4 as stated here, then why not 0.8.6 which is the latest released version)?
Upgraded to 0.8.6. Now it works. Thanks.
Great! Closing.