Hope that anyone can help.

I tried posting this problem before but can't find it. Hopefully more luch this time.

I can't edit my profile when I am in CMS. I get the follow erros that don't really help me. It seems that it went wrong when I installed the forum (dailybuild 12-11-2008). Currently working with v2.2.3. and Dutch Language pack. Errors generated are

FATAL ERROR: FieldSet::addFieldToTab() Tried to add a tab to a FieldSet object - 'Root' didn't exist.
At line 142 in C:\Program Files\xampp\htdocs\hoogeerd\sapphire\forms\FieldSet.php

user_error(FieldSet::addFieldToTab() Tried to add a tab to a FieldSet object - 'Root' didn't exist.,256)
line 142 of FieldSet.php

FieldSet->findOrMakeTab(Root.Forum)
line 55 of FieldSet.php

FieldSet->addFieldToTab(Root.Forum,TextField,FirstName)
line 160 of ForumRole.php

ForumRole->updateCMSFields(FieldSet)
line 395 of Object.php

Object->extend(updateCMSFields,FieldSet)
line 804 of Member.php

Member->getCMSFields()
line 1074 of Member.php

Member_ProfileForm->__construct(CMSMain,Member_ProfileForm,Member)
line 763 of LeftAndMain.php

LeftAndMain->Member_ProfileForm()
line 756 of LeftAndMain.php

LeftAndMain->myprofile(Array)
line 261 of Controller.php

Controller->run(Array)
line 104 of Director.php

Director::direct(/admin/myprofile)
line 158 of main.php

Context

--------------------------------------------------------------------------------

Debug (Debug::showError() in line 180 of Debug.php)
this =
dataobject set
HeaderField (: Persoonlijke Gegevens : ) =
TextField (FirstName: Voornaam : ) =
TextField (Surname: Achternaam : ) =
HeaderField (: Gebruikers Gegevens : ) =
TextField (Email: Email : ) =
DropdownField (Locale: Interface Taal : ) = nl_NL
ConfirmedPasswordField (Password: : ) =
HeaderField (: OpenID/i-name credentials : ) =
LiteralField (OpenIDDescription: OpenIDDescription : ) =
TextField (IdentityURL: OpenID URL/i-name (e.g. http://openid.silverstripe.com/) : ) =
tabName =
Root.Forum
parts =
0 =
Root
1 =
Forum
currentPointer =

part =
Root
parentPointer =
dataobject set
HeaderField (: Persoonlijke Gegevens : ) =
TextField (FirstName: Voornaam : ) =
TextField (Surname: Achternaam : ) =
HeaderField (: Gebruikers Gegevens : ) =
TextField (Email: Email : ) =
DropdownField (Locale: Interface Taal : ) = nl_NL
ConfirmedPasswordField (Password: : ) =
HeaderField (: OpenID/i-name credentials : ) =
LiteralField (OpenIDDescription: OpenIDDescription : ) =
TextField (IdentityURL: OpenID URL/i-name (e.g. http://openid.silverstripe.com/) : ) =

Can anyone give some advice or help me solve this problem.