Hi Mazzle, I spoke to you the other night. After browsing around for a bit, I wasn't able to locate the post you referred to, but I took a screenshot to further help any troubleshooting.
Edit: As you can see, the black box to the left is the box that is supposed to sit behind the combat log to the right. Also, the trinket and drink/food autobar is to the left.
As I said the 'Press the button to complete the spell' appears for a moment near the top of the screen then disappears. This is at a 1680x1050 resolution. The UI works marvelously on two other accounts and 4 other characters on this same account without any problems.
Any tips would be much appreciated.
Regards,
JadoJodo