Position jitter when using GUIUtility.RotateAroundPivot

I's trying to make a GUI like what I have shown below that uses text that is rotated by 90 degrees.

I'm having a strange problem that seems to only affect the rotated text, it's position jitters as the GUI moves across the screen. Below is the code:

         Vector3 pos = Camera.main.WorldToScreenPoint(transform.position);
         pos.y = Screen.height-pos.y;
         float hW = hudFrame.width*hudScale;
         float hH = hudFrame.height*hudScale;
         GUI.BeginGroup(new Rect(pos.x-hW+hudOffset.x, pos.y-(hH/2)+hudOffset.y, hW, hH));
         GUI.DrawTexture(new Rect(0, 0, hW, hH), hudFrame);
         float pHealth = (_pc.GetHealth()/_pc.maxHealth);
         float hBarHeight = (healthBar.height*hudScale)*pHealth;
         GUI.DrawTexture(new Rect(432*hudScale, (55*hudScale)+((healthBar.height*hudScale)-hBarHeight), healthBar.width*hudScale,hBarHeight), healthBar);
         List<PowerUp> powers = _pc.GetPowers();
         float sH = selector.height;
         int curSel = _pc.GetSelectedPower();
         GUI.DrawTexture(new Rect((95-16) * hudScale, (57 + (38*curSel) + (198 * curSel) - 16)*hudScale, selector.width * hudScale, sH * hudScale), selector);
         for(int i = 0; i < powers.Count; i++)
         {
             GUI.Box(new Rect(95 * hudScale, (57 + (38*i) + (198 * i))*hudScale, 198 * hudScale, 198 * hudScale), powers[i].ToString());
         }
         GUI.EndGroup();
         GUI.skin = skin;
         GUI.BeginGroup(new Rect(pos.x+hudOffset.x, pos.y-(hH/2)+hudOffset.y, hH, hW));
         GUIUtility.RotateAroundPivot(90, new Vector2(0,0));
         GUI.Label(new Rect(67*hudScale, 230*hudScale, 250, 25), powers[curSel].ToString());
         GUI.Label(new Rect(771*hudScale, 190*hudScale, 250, 25), (pHealth*100)+"%");
         GUI.EndGroup();

Is there a way to correct this issue?