google site map upload question

My question is:

in google webmaster tools there is the option to re-upload/location of your site map... when vbseo sitemap gen creates new sitemaps is it better to re upload the new site map file although the file name is the same or is it better to let google just re download the updated file?

you should only submit
yourdomain.com/sitemap_index.xml.gz
or
yourdomain.com/forums/sitemap_index.xml.gz
depending on where you have your site.

from there, google will pick it up nearly daily.

There is no need to resubmit sitemap every time it is generated on your site. vBSEO Sitemap Generator pings Google (and other SEs) automatically.

great guys thank you so much... one more quick question... once the URL # gets over the 50,000 google limit... does the generator great two... labeled accordingly:

sitemap1
sitemap1

or how exactly does it work?

Yes, sitemaps are automatically splitted on multiple files in this case.

so once my forum requires multiple sitemaps, do need to upload the new one (2nd one) to google webmaster tools?

Nope,
The index file is simply a list of _1, _2, _X sitemaps locations

awesome guys thanks for all the help... great product so far from what i can see! very please.