UK Company is a US Subsidiary, Getting a W-2?

I work for a UK company that is a subsidiary of a US company.  The UK company gives us stock grants once a year (as a bonus).  These grants are taxed 40% by the Home Office.  These grants are also reported by the company to the IRS via a W-2.  Now, I made 100% of my income from my job with the UK company, but the way I read the 1116 forms, the stock grant income is US income, so I can only use X% of my UK income tax as a Foreign Tax Credit (X=1-percentage of total income that stock grant is).  The X% of my UK income tax doesn't cover my total IRS tax liability, so I am effectively paying duplicate tax on this stock grant income (ouch!).  Does this sound right?  Does anyone else have a situation where they get a W-2 but don't work in the US or have US income at all?  Does anyone else get this hands-on with their taxes or just pay someone else to take care of it ?

Thanks,
Gregory