Switching from glOrtho to glFrustum

I am working on a simple 3D game. However the menu part of the complete game 2D. I use 2 function to switch the 2D or 3D.

- (void) Setup3DView {
 glLoadIdentity(); 
 glViewport(0, 0, 320, 480);
 const GLfloat lightAmbient[] = {0.2, 0.2, 0.2, 1.0};
 const GLfloat lightDiffuse[] = {1.0, 1.0, 1.0, 1.0};
 
 const GLfloat lightPosition[] = {5.0, 5.0, 15.0, 0.0}; 
 const GLfloat light2Position[] = {-5.0, -5.0, 15.0, 0.0};
 const GLfloat lightShininess = 0.0;
 const GLfloat zNear = 0.01, zFar = 800.0, fieldOfView = 45.0; 
 GLfloat size;
 glEnable(GLDEPTHTEST);
 glMatrixMode(GL_PROJECTION);
 
 size = zNear * tanf(DEGREESTORADIANS(fieldOfView) / 2.0);
 glFrustumf(-size, size, -size / (320.0/480.0), size / (320.0/480.0), zNear, zFar); 
 glMatrixMode(GL_MODELVIEW);
 glShadeModel(GL_SMOOTH); 
 glEnable(GL_LIGHTING);
 glEnable(GL_LIGHT0);
 glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);
 glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);
 glLightfv(GL_LIGHT0, GL_POSITION, lightPosition); 
 glLightfv(GL_LIGHT0, GL_SHININESS, &lightShininess);
 
 glEnable(GL_LIGHT1);
 glLightfv(GL_LIGHT1, GL_AMBIENT, lightAmbient);
 glLightfv(GL_LIGHT2, GL_DIFFUSE, lightDiffuse);
 glLightfv(GL_LIGHT2, GL_POSITION, light2Position); 
 glLightfv(GL_LIGHT2, GL_SHININESS, &lightShininess);
 glLoadIdentity(); 
 glClearColor(0.0f, 0.0f, 0.0f, 1.0f); 
 printf("Moving to 3D View ");
 glBlendFunc(GL_ONE, GLONE_MINUS_SRCALPHA);
 glEnable(GLTEXTURE2D);
 glTexEnvi(GLTEXTUREENV, GLTEXTURE_ENVMODE, GL_REPLACE);
 glEnableClientState(GLVERTEXARRAY);
 glEnableClientState(GLTEXTURE_COORDARRAY);
 
 glEnable(GL_BLEND);
 glBlendFunc(GLSRCALPHA, GLONE_MINUS_SRCALPHA);
}

- (void) Setup2DView {
 CGRect rect = CGRectMake(0, 0, 320, 480);
 glViewport(0, 0, rect.size.width, rect.size.height); 
 
 glLoadIdentity();
 
 glMatrixMode(GL_PROJECTION);
 glOrthof(0, rect.size.width, 0, rect.size.height, -1, 1);
 glMatrixMode(GL_MODELVIEW);
 
 glBlendFunc(GL_ONE, GLONE_MINUS_SRCALPHA);
 glEnable(GLTEXTURE2D);
 glTexEnvi(GLTEXTUREENV, GLTEXTURE_ENVMODE, GL_REPLACE);
 glEnableClientState(GLVERTEXARRAY);
 glEnableClientState(GLTEXTURE_COORDARRAY);
 
 glEnable(GL_BLEND);
 glBlendFunc(GLSRCALPHA, GLONE_MINUS_SRCALPHA);
}

My problem is: I got both function working fine when they are called initially but when I Switch from on to other I get some problem.

When I setup 2d view a to show the menu first and then change the view to 3D, the view is completely lost in space and is drawn crazy n far away.