I deleted some of the profile properties in "User Accounts" e.g. Middle name etc.
Now when i trie to log in with any user, except the host user, i get an error message:
"Input+string+was+not+in+a+correct+format.&content=0"

In the log the following is shown:

AssemblyVersion: 03.03.05
PortalID: 0
PortalName: xxxxxxx
UserID: 2
UserName: admin
ActiveTabID: 36
ActiveTabName: Home
RawURL: /Home/tabid/36/ctl/Login/Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://www.advendo.nl/
UserAgent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AtHome033; (R1 1.3); .NET CLR 2.0.50727)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 5315de5e-3bc9-4000-9230-2c578217af78
InnerException: Input string was not in a correct format.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Number.ParseInt32
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: Input string was not in a correct format. ---> System.FormatException: Input string was not in a correct format. at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) at DotNetNuke.Entities.Users.UserProfile.get_TimeZone() at DotNetNuke.Entities.Users.UserTime.get_ClientToServerTimeZoneFactor() at DotNetNuke.Entities.Users.UserTime.get_CurrentUserTime() at DotNetNuke.UI.Skins.Controls.CurrentDate.Page_Load(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain() --- End of inner exception stack trace ---
Source:
Server Naam: WWEB01

What is wrong here and does anyone know how i can correct this?