body field in smf_tp_articles defaults to text from longtext on upgrade

[Rafferty]

Link to my site: https://aadaa.asn.au
SMF version: SMF ver. 20RC4
TP version: TP ver. 1.0 rc1
Default Forum Language: english
Theme name and version: default
Browser Name and Version: firefox/google/ie/
Mods installed: numerous

Heres a reoccurring problem: every time theres an upgrade, I lose my long articles which cut off half way through the txt. It seems that the body field in smf_tp_articles defaults to text from longtext on upgrade causing the loss off half the text in articles. Is this a known problem or just mine and how can i get over this? Its getting to be like ground hog day.