Old URLs in Index

We changed our URL structure in April. During that time...we've increased our in-bound links, increased keyword density, etc.

Google found the new links in 3 days. Additionally, we are ranking in top 10 in G's SERPs for many competitive keywords in our vertical.

Yahoo is still displaying our old URLs from 4 months ago in thier SERPs. We are using 301 redirects (G found them fine).

Anyone have suggestions or similar stories?

Thanks for your time.

[edited by: DaveAtIFG at 5:24 pm (utc) on July 13, 2004]
[edit reason] Removed off topic remarks [/edit]

4 months old