We are aware of this problem, we have planned to resolve it in 2 ways in the next releases of TXM.

1) We have reimplemented the token.pl script of TreeTagger in Groovy.
But we haven't had the time to plug it in as an option for TXM tokenization.
See in the Toolbox sources : src/groovy/filters/TTTokenizer.groovy

2) We also have another Tokenizer with more parameters which is able to solve that problem. But also not yet pluged.
See in the Toolbox sources : src/groovy/filters/TEITokenizer.groovy

Matthieu Decorde