Publish custom assembly with query

My custom assembly works in design mode but when i publish it :

- function without query work well.

- function with query return an error (#Error).

The assembly was copied in C:\Program Files\Microsoft SQL Server\MSSQL\Reporting Services\ReportServer\bin

What can i do the use query in my custom assembly.

Thanks for all your answers.

Have you looked at this article.

http://support.microsoft.com/default.aspx?scid=kb;en-us;842419

Problems with custom assemblies are usually related to not granting the correct permissions to the assembly in the config files.