In the IPB admin area i seen errors with Suhosin:

Suhosin Enabled
The minimum recommended value for the configuration option 'suhosin.post.max_vars' is 4096, however your value is 1000. Your host will need to change this in the php.ini file.

Suhosin Enabled
The minimum recommended value for the configuration option 'suhosin.post.max_vars' is 4096, however your value is 1000. Your host will need to change this in the php.ini file.

Suhosin Enabled
The minimum recommended value for the configuration option 'suhosin.post.max_vars' is 4096, however your value is 100000. Your host will need to change this in the php.ini file.

Suhosin Enabled
The minimum recommended value for the configuration option 'suhosin.post.max_vars' is 4096, however your value is 100000. Your host will need to change this in the php.ini file.
i fixed these by adding following lines into my server php.ini (in my case: /usr/local/lib/php.ini):
suhosin.post.max_vars = 4096
suhosin.request.max_vars = 4096
suhosin.post.max_value_length = 1000000
suhosin.request.max_value_length = 1000000
suhosin.get.max_value_length = 2000
suhosin.request.max_varname_length = 350

then service httpd restart (restart Apache) - this step should not be needed

Some hosting providers allow their users to add php.ini file in their website root folder and set these values themselves. But if it dont works (ie: you see 500 server error) you may need to try to contact hosting provider to change it and or you may skip this and let the Suhosin warnings be in IPB admin area. Im not sure if its too bad to keep these errors.