I did some quick research and figured out your tax issue. Some background on how the ad valorem/local county tax system goes in Texas.
Producing minerals are subject to ad valorem taxation in Texas.
The County Appraisal District is in charge of the appraisal/valuations of your producing oil & gas interests (also real property, business, personal property, utilities, etc.).
Almost all of the County Appraisal Districts in Texas hire private consulting groups on a contract basis to do the leg work of appraising these minerals and updating ownership.
Ward Co. is represented by Pritchard & Abbott, Inc. (http://www.pandai.com/home.aspx). P&A represents the majority of counties in Texas.
Winkler Co. I believe is represented by P&A as well but it may be Capitol Appraisal Group (http://www.capitolappraisalgroup.com/).
The consulting group provides the Appraisal District with the information. Notices of Value are sent out, Protests are filed for a myriad of reasons, and then in mid-July (right around now actually) the Appraisal Review Board hears the protests by the parties present or those who send in affidavits. The ARB votes and their decision is the final determination.
The next step is Certification which is July 20th.
Date ARB must approve appraisal records, but may not do so if more than 5 percent of total appraised value remains under protest. The board of directors of a CAD with a population of 1 million or more may postpone the deadline to Aug. 30 or increase the threshold percentage from 5 to 10 percent of the appraised value of properties not under protest (Sec. 41.12).
County Tax Assessor or County Tax Assessor & Collector's office - The County Appraisal District then passes the appraisals to the Assessor's office. 2 separate groups. Some counties are 1 in the same. But majority are separate. The Assessor is who mails you on Oct 1st the Tax Bill with what you owe in ad valorem taxes.
I know the solution to your problem but doubt you want me to post. I'll send a request and advise your situation.