Add custom styles to the SummaryLinkWebPart. This technique can also be applied to the TableOfContents WebPart and the Content Query WebPart

Create a custom page that replaces a SharePoint application page. AccessDenied, Confirmation, Error, Login, RequestAccess, Signout, WebDeleted

I wrote web part that uses Repeater control to create some repeating blocks of output. Each of these blocks has Button control in it. When I ran web part under SharePoint I got the following error: Invalid postback or callback argument.

See here how I solved the SQL server detected a logical consistency-based i/o error