php crash and memory_limit

Hi I'm having a problem with file uploads and freezings of the php-module in apache. Yes I have googled and RTFM:ed but I don't get any good results out from what I have tested so far. I have set MAX_FILE_SIZE as a hidden value in the form, the value is set to "400000" I increased 'memory_limit' from 8M to 200M in my home server and it all worked, when I then tested the same thing on the web-hotel I got 'Internal server error 500' and I was unable to access files in the same directory as the problematic page was in. I did it with "ini_set(" in the page. Since my web-hotel won't change any settings I have to either configure with ini_set or the .htaccess file. I set LimitRequestBody to 16M in a .htaccess file since many have suggested that this would solve the problem. But not. I think these variables can be set in .htaccess but I don't get the correct syntax in the file, i'm just getting 'internal server error' all the time. php_value memory_limit 34M php_value post_max_size 33M php_value upload_max_filesize 32M php_value max_execution_time 600