hmm i think this hack and who is online produce a big problem i tested it now some hours and here my description, sorry my english is not the best but i will do my best.
i´m using a german ubb 6.05 and and installed who is online 4.0.0 and you hack, before was no problems but now when i installed this 2 hacks comes the problem that 1 time no one can repley to an topic, the board say there is no posting there to answer or it is deleted. making new topics works..
ok i using my backup and it works then. next hack attempt: self as before but this time can no one post a new topic but repley then O_o.
then i installed i only who is online, all works perfect now for 3 hours or so...
oh another important thing is that the board works after the 2 hacks a half or 1 hour without problems, after that time come that all.
another interesting thing is that i try to remove only the galaga hack and bring the files back, it happen nothing, only with the backup works it right.
*phew* i hope the discription of the problem is ok.