Are you saying this is a series for which the plugin failed to add missing seasons/episodes, but did add all seasons/episodes after the series was deleted and re-added? If so, what was the series? Are you able to recreate the state where the seasons are incomplete and the plugin is unable to add the missing ones?
First, my apologies for bad terminology.
Yes, this is exactly how it happened. The series was Tudors (tt0758790), I had data for 2 first seasons and there are 4 seasons. I deleted series record and then added it again with NMM tool and it pulled in all 4 seasons with all episodes.
I tried next that I deleted 1 episode from season 3 (from Tudors) and imported data from IMDB, missing episode was not added. The same happened with the TVDB plugin. From URLs, it was possible to see that all 4 seasons were scanned with IMDB, however, TVDB plugin went briefly and I'm not sure what it did. Is there btw any possibility to see e.g. from log files or text files what is actually retrieved? I think that with Lost, only season 1 is scanned (based on URL shown at the bottom), so this could be some plugin issue. However, Tudors seemed to work ok with all the seasons. Next I added the missing episode manually, run both plugins but it was not updated. Next, I added url into episode and then it was updated correctly.
So, it appears that data is mined from IMDB correctly and is not missing. However, at processing, something prevents it to be added into db. Btw, I'm using latest official release, not beta. 0.9.9.21 is the version number. Also, this may be important, I am using option that deleted data is not deleted from db, it is just marked inactive I guess. Also, I have originally imported data for these series with older version, like 2 years ago. I have developed some data mining software for personal use so it looks to me that this part is ok, but, something goes wrong when parsed data is tried to be used i.e. updated into db. Some condition prevents to add it correctly/only updates existing episodes. Related to that, episodes information is very brief with only a few data fields. However, if I select episode & import data, many more fields are actually retrieved. Maybe this is on purpose, I don't know.
I have a few similar series on my db for testing purposes if you have any suggestions