Loading H4xx0r into Fl Studio (v5&6) has been giving me "access violation" errors. 

Until this is fixed, the solution is this:
Insert H4xx0r as a channel
Save flp
Exit FL Studio
Reopen FL Studio
Reopen saved flp

H4xx0r will now load properly, at least for me.
Please let me know if you have any problems in FLS, or any other host.

sk.