After much trying switching off 'Bio' finally solved my WSOD problem. Some more info:
My site has 64 mb of php memory
It is a multisite, only the domains for which bio was enabled gave the wsod, though on an irregular basis, sometimes one domain failed, sometimes all.
Clearing the cache had no effect,
Switching of the Event-related modules neither
My server error log showed repeats of these two lines. 

PHP Notice:  Undefined index:  q in /home/www/klimatosoof/sites/all/modules/bio/bio.module on line 28
PHP Notice:  Undefined index:  q in /home/www/klimatosoof/modules/ecommerce/cart/cart.module on line 117

First I uninstalled BIO and my site was then back again. Afterwards I also corrected the e-commerce 'problem' but I do not know whether that one really caused troubles.

So possibly goodbye for bio. When it didnt cause a WSOD It worked allright though I very much missed a block option. (Nodeasblock is still more a 'story' then a 'block' ).
TR

Comments

jscheel’s picture

jscheel commented
Status: Active » Closed (won't fix)

That is a PHP Notice, which is not a fatal error. The worst you will get is a returned value of null when trying to access an index that doesn't exist. Take a look at the Predefined Constants table here http://us2.php.net/manual/en/ref.errorfunc.php:

Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.

theorichel’s picture

theorichel commented

Thank you, but I have no clue how to interpret this Predined Constants Table, it is way above my head. I have uninstalled Bio but the WSOD's keep on coming and appear related to Internet Explorer, though they are not local (manmy of my users have them). So there must be something in my site that gives me these WSOD's and as for the other errors: when I am done with the WSOD's I will reinstall Bio and we'll see then.

Thanks so far.