I get a CTD when I hit next turn. What to do?

I had such a good immoral Greece->England game going on...
Edit:
[Mar 28, 2011 - 22:37:38] Messages while processing 'Resource/Civ4.thm'
Error : Decl - ('Civ4Theme_Common.thm', Ln:401, Col:13) Assignment source propertyId 'SF_CtrlTheme_Civ4_Control_Font_Size3_Italic' not found
Error : Decl - ('Civ4Theme_Common.thm', Ln:402, Col:13) Assignment source propertyId 'SF_CtrlTheme_Civ4_Control_Font_Size3_BoldItalic' not found
Error : Decl - ('Civ4Theme_Common.thm', Ln:408, Col:13) Assignment source propertyId 'SF_CtrlTheme_Civ4_Control_Font_Size1_Bold' not found
Error : Decl - ('Civ4Theme_Window.thm', Ln:3048, Col:9) Assignment source propertyId 'SF_CtrlTheme_Civ4_Control_Font_Size1_Bold' not found
Error : Syntax - ('Civ4Theme_HUD.thm', Ln:887, Col:13) Unexpected '.' in the identifier assignment statement
Error : Syntax - ('Civ4Theme_HUD.thm', Ln:927, Col:13) Unexpected '.' in the identifier assignment statement
- I haven't changed anything in the files apart from some minor stuff that I'm quite sure is unrelated to this.