I'm not quite sure what you mean about the different dates, but it sounds like you've run into a problem with the judge not being willing to accept the waiver of service because it doesn't appear to have been signed after the petition was filed. To get past that, you're going to have to be able to prove that you first filed the petition, then took a copy of the filed petition and gave it to him along with the waiver of service (which says that he acknowledges receiving a copy of the filed petition). If you instead got the petition ready to file, made a copy of the unfiled petition, gave that to him with the waiver, then filed the signed waiver and petition at the same time, I'm afraid that's not valid and there's no way to make it valid after the fact (but, only the service issue needs to be addressed, the petition should be okay). About the only options you have, unless he wants to file an answer or show up in court, are to get him a copy of the filed petition and get him to sign a new waiver of service based on that, or get him officially served (which costs you a little more, but doesn't require him to sign anything). Good luck.
If your husband signed the waiver then why do you need to locate him? Does it say his signature is required to finalize the divorce? If you haven't been able to serve him then you can request alternate method of service like having the process server post on his door. This may be over your head and you may be required to hire an attorney.
Quite frankly, it is up to the judge on whether or not the waiver is acceptable. You can go to your court one morning and ask to approach the associate judge of your court and explain the situation. If the judge says that the Waiver of Service is unacceptable, then you have no choice but to either (1) have your husband execute a new one or (2) serve him.
If you cannot serve him, then there is a divorce by publication. These are complex and technical. Also, in Harris County the courts will appoint an attorney to represent your husband and YOU WILL PAY FOR THIS ATTORNEY before the divorce is granted. The cost varies but they can run anywhere from $500-$1,500.
If you have no money, there are pro bono organizations to assist you. Houston Volunteer Lawyers is one of the groups. Their phone number is 713-228-0732. Also, all the law schools in Houston have legal clinics. You can call them too.
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