Sharepoint, error on adding a webpart to a totally new page

I have a problem on adding a webpart to sharepoint page.

I have a blank page in the sharepoint, and I have a custom control uploaded to the site, on adding the webpart the the sharepoint page I get the following error:

"Attempted to use an object that has ceased to exist. (Exception from HRESULT: 0x80030102 (STG_E_REVERTED))"

I get that error even if the sharepoint page is totally blank and so is the web part.

If you have access to the server file system, look at "ULS trace" files found at c:\program files\common files\microsoft shared\web server extensions\12\logs. There is a lot of information - much more than you need. Search for the name of your ascx file.