Midori Rotaru

Its probably the browser using has not got the correct certificate. Just log into your my second life (ie here ) using Microsoft explorer one time the required certificate wil be downloaded automatically. Then retry in worls should be ok.

Are many possibility ...but an idea would be to check your graphic preferences .From the walk comment i would check if your view draw distance has not been set high.That can have a direct effect I change it as needed sometimes 500+ but usually I keep less than 100. The other graphic preferences can reduce to see if improves performance . May work may not if not then we can see if another idea .