I downloaded an MP4 movie with 2 parts and have a single .srt subtitle file. I used VSO ConvertX to dvd to convert and add the subtitles. Both parts of the movie and subtitle filewere in the same folder. Under the subtitle menu it said 1 internal for each part of the movie. Now that it has finished converting I am hesitant to burn the DVD because I am not sure the subtitles will be there. I have tried to test with Win. Media Player and Win DVD and i cannot see the subtitles but the menu feature I chose is there but no subtitle option available.
Since the movie was in 2 parts and the subtitles in one, do you think that would cause a problem adding them the singlesub file to a 2 part movie? Also, if not, will the subtitles play correctly when i burn the dvd?
The subtitles play perfectly with BS player.

I opened the movie with windvd and the subtitles were there for part 1 of the movie but were listed as ABKHAZIAN not english but they showed in english. Part 2 however, has the menu asenglish but there are no subtitles showing in this part. What should I do?

If you have only one file for subtitles then they will not be correct after conversion.
You need to split that subtitle file with subtitle editor or get correct 2-part subtitle files.
Before conversion you need to check that subtitles have correct language settings.