backup getting larger and larger

I still have to investigate if the tables are getting really
larger... but at a first guess there shouldn't be any good reason to
see tables getting so large so fast... so I was wondering if
anything could contribute to make a backup much larger than it was
other than table containing more records?

The only thing that should have been really changed is the number of
concurrent connections during a backup.

thanks

--
Ivan Sergio Borgonovo
http://www.webthatworks.it