I think I have find the Problem...

When the Forum has an User, and the Joomla not, for example, "Test", and you will log in with "Test" in Joomla, and Joomla doesn't know, that TEST is exist, than you become an Blank Screen...

The Problem is coming, when you install the Forum and use another Name for the Administrator than "admin"... Is it absolutely recommend that you using the Adminsitrator-Name "admin" ... not your Nickname or so... And then, when the Forum is installed you can use another Name like your Nick, and turn it into the Admin-UserGroup so that you have two or more admins in there... BUT THE NICK "admin" MUST BE IN THE GROUP!! Because Joomla is using the adminaccount with the Nick "admin" and when the Name is not in SMF, you have a Problem...

Also... you must input at First the admin in the Forum... than you registry your Nick in Joomla and than turn your Nick in the SMF into the adminUserGroup.

Bevor you registry, you must delete your Nick in the Forum!

Okay... thats all... I hope...

AND check your Users... When you will log in in Joomla, the User must also be in Joomlas User-Manager... Look in it in the Backend... When the User is not there, but in the Forum, than you must first delete the User in the Forum and then register FIRST in Joomla, and then the User will Automaticaly transferen also in the SMF...

Oh... there can be a lots of more Problems...

First, you must Install the Forum in an extra directroy for example /forum

than you must install the database-entrys in the same database. like joomla... BUT DO NOT EDIT THE PREFIX...

Bevor you are patching the index.php from the SMF and the Joomla, please test the Forum and the joomla...

THEN bevor you patching, change the settings in the SMF, for example, the database connection must switch to allways... For more Infos, look in the Guide and do the install like the steps in the guide... You must only have one Error in the Install, and the Blank Screen is looking at you...

When you have more Problems, I can help you by the install... Or I can install all...

You can contact me by email...

mdman@mdman.de

Okay...

Okay... When you are Using the new index.php than you have this Problem...

Look in the guide, and then follow the instructions...

I have at first delete the original index.php and then I have put the index.php from here to my server and then i have also a blank screen...

Than I delete all, installed the joomla and SMF and then I have step by step made, what the guide said... and now, its running...

I have patched the index.php with the Components-congfig Menü in Joomla Backend... I haven't delete or patched the index.php by copy another...

Here the Guide...
http://www.joomlahacks.com/component/option,com_remository/Itemid,41/func,fileinfo/id,448/

Load it and make the install exactly so and then the Server will run... and Joomla and SMF also...

wardesign:
I have also that Problem...

When I registry me in Joomla, than it is all Great...

but when I registry me at first in the SMF, and then I close my browser and than I turn it on and load the Joomla-side, and logged me in with the Data from SMF in Joomla, than I have a blank screen...

I think, the index.php is not realy patched... there is somewhere an ERROR... please check it up...

Thanks a lot...

MDMAN

EDIT:

@wardesign and all the Rest:

I think I have find the Problem...

When the Forum has an User, and the Joomla not, for example, "Test", and you will log in with "Test" in Joomla, and Joomla doesn't know, that TEST is exist, than you become an Blank Screen...

The Problem is coming, when you install the Forum and use another Name for the Administrator than "admin"... Is it absolutely recommend that you using the Adminsitrator-Name "admin" ... not your Nickname or so... And then, when the Forum is installed you can use another Name like your Nick, and turn it into the Admin-UserGroup so that you have two or more admins in there... BUT THE NICK "admin" MUST BE IN THE GROUP!! Because Joomla is using the adminaccount with the Nick "admin" and when the Name is not in SMF, you have a Problem...

Also... you must input at First the admin in the Forum... than you registry your Nick in Joomla and than turn your Nick in the SMF into the adminUserGroup.

Bevor you registry, you must delete your Nick in the Forum!

Okay... thats all... I hope...