PassiveTeX uses quite a lot of TeX's resources. You may find it necessary to increase the size of some of TeX's resource pools by editing the file %%LOCALBASE%%/share/texmf/web2c/texmf.cnf with any text editor. If you change %%LOCALBASE%%/share/texmf/web2c/texmf.cnf, delete the word "original" on line 1 of the file. This will prevent future installations of TeX from overwriting changes you've made.