With the new version (beta address) it will not let you go over 50megs.

going to the address www.yousendit.com will redirect you to beta.yousendit.com which gives you that 50meg max

i find that if i type in this address - it will lead me to the "old" unrestricted site.
http://www.yousendit.com/default.uplx

not sure how long this is going to last, but for the time being.....