FroYo post upgrade problems

[Guest Argonaut]

I had a vanilla SGS . upgraded yesterday to official FroYo release using KIES

Phone took a couple of power cycles before it would start up.

All working but now seems jerky in response, zooming less smooth response often delayed, have had many apps fail to respond-goes black screen. No buttons work..after about a minute get popup advising app has stopped responding, and have to force quit.

Happens on different apps.

Not had one instance of this prior to upgrade.

Noticed on email that whereas previously I could scroll through mails and it would check for new ones in background ... it now stops you doing anything ... can't even scroll window until it's finshed checking/loading emails.

Is there a way of redoing upgrade..without losing config or apps .... or restoring config afterwards ... apps I can download again.