nelze obj. zboží

zravim, při pokusu objednání z teto stranky http://www.auto-pilot.cz/podvozek/tlumice-pruziny- a-prislusenstvi/zadni-naprava/dorazy-a-prachovky/C atalog.aspx?tree=0&path=0001314088;1960702;1960703 ;1963664;1963681;1963687;1963691&list=1

něco tam píše o net framevork, mám verzi 3.5 nainstalovanou

Server Error in '/' Application.
The state information is invalid for this page and might be corrupted.
Descriptikn: En unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: The state information is invalid for this page and might be corrupted.

Source Error:

[No relevant source lines]

Source File: c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temp orary ASP.NET Files\root\d8da2b47\a814b499\App_Web_default.aspx. cdcab7d2.bmbts5oi.0.cs Line: 0

Stack Trace:

[FormatException: Invalid character in a Base-64 string.]
System.Convert.FromBase64String(String s) +0
System.Web.UI.ObjectStateFormatter.Deserialize(Str ing inputString) +72
System.Web.UI.ObjectStateFormatter.System.Web.UI.I StateFormatter.Deserialize(String serializedState) +4
System.Web.UI.Util.DeserializeWithAssert(IStateFor matter formatter, String serializedState) +37
System.Web.UI.HiddenFieldPageStatePersister.Load() +113
Prosím jakékoli návrhy, děkuji