SMHP timeout

[Yej]

How to find why SMHP timeout error occurs. LOG shows below lines:

MAJOR 11/12/2012 1:44:34 PM
UI Timeout (limit: 20s) -- Nav

WARNING 11/12/2012 1:44:29 PM
UI Webapps Loading Timeout -- Nav Load Time: 20s [Webapp-List: HP]

MAJOR 11/12/2012 1:39:47 PM
UI Timeout (limit: 20s) -- Nav

WARNING 11/12/2012 1:39:43 PM
UI Webapps Loading Timeout -- Nav Load Time: 20s [Webapp-List: HP]

MAJOR 11/12/2012 1:38:17 PM
UI Timeout (limit: 20s) -- Nav

WARNING 11/12/2012 1:37:55 PM
UI Webapps Loading Timeout -- Nav Load Time: 20s [Webapp-List: HP]

INFORMATIONAL 11/12/2012 1:37:33 PM
Single Sign On User:****** from *.*.*.* was authenticated and authorized with 'Administrator' rights to invoke target URL=https://*****:2381/

Thanks.