php - Unreachable website -

i have problems website being ureachable every few minutes. happens when try upload photos , site becomes unreachable. if try proxy works fine @ same time. if in errorlog fills errors "file not found...".

i have been using cloudflare development mode on. when site unreachable gives cloudflare error this: http://shrani.si/f/1a/ly/pciy0el/cf1.jpg use htaccess friendly urls.

.htaccess:

#---------www fix-------# rewriteengine on rewritecond %{http_host} !^www\. rewriterule ^(.*)$ http://www.%{http_host}/$1 [r=301,l]  #---gzip compression----# ######################### <ifmodule mod_gzip.c> mod_gzip_on yes mod_gzip_dechunk yes mod_gzip_item_include file .(html?|txt|css|js|php|pl)$ mod_gzip_item_include handler ^cgi-script$ mod_gzip_item_include mime ^text/.* mod_gzip_item_include mime ^application/x-javascript.* mod_gzip_item_exclude mime ^image/.* mod_gzip_item_exclude rspheader ^content-encoding:.*gzip.* </ifmodule>  #-----files expire------# ######################### addcharset utf-8 .php <filesmatch ".(ico|pdf|flv)$"> header set cache-control "max-age=29030400, public" </filesmatch> <filesmatch ".(jpg|jpeg|png|gif|swf|css|js)$"> header set cache-control "max-age=604800, public" </filesmatch> <filesmatch ".(xml|txt)$"> header set cache-control "max-age=172800, public, proxy-revalidate" </filesmatch> <filesmatch ".(html|htm|php)$"> header set cache-control "max-age=60, private, proxy-revalidate" </filesmatch>  ######################### #-----friendly url------# options -indexes options +followsymlinks  rewritecond %{script_filename} !-d rewritecond %{script_filename} !-f   #user rewriterule ^([a-z]{2})/user/([0-9]+)([/])?$ user.php?user=$2&language=$1 rewriterule ^([a-z]{2})/user/([0-9]+)/public([/])?$ user.php?        user=$2&view=public&language=$1  #tractor-list rewriterule ^([a-z]{2})/tractors([/])?$ tractor-list.php?language=$1 rewriterule ^([a-z]{2})/tractors/([0-9]+)/([a-za-z0-9\-]+)([/])?$ tractor-list.php?    manufacturer=$2&language=$1  #tractor-model #just tractor rewriterule ^([a-z]{2})/tractor/([0-9]+)/([a-za-z0-9\-\.]+)([/])?$ tractor.php?    tractor=$2&language=$1 #tractor , component rewriterule ^([a-z]{2})/tractor/([0-9]+)/([a-za-z0-9\-\.]+)/([a-z]+)([/])?$     tractor.php?tractor=$2&language=$1&component_type=$4 #tractor,component,component id rewriterule ^([a-z]{2})/tractor/([0-9]+)/([a-za-z0-9\-\.]+)/([a-z]+)/([0-9]+)([/])?$ tractor.php?tractor=$2&language=$1&component_type=$4&component_id=$5  #home rewriterule ^([a-z]{2})/home([/])?$ index.php?language=$1 rewriterule ^([a-z]{2})([/])?$ /$1/home [r=301,l]  #compare rewriterule ^([a-z]{2})/compare/([0-9]+)/([0-9]+)([/])?$ tractor-compare.php?    language=$1&tractor1=$2&tractor2=$3 

part of erreorlog:

[tue may 21 03:16:43 2013] [error] [client 193.189.190.66] file not exist:        /home/162175/domains/sitename.com/html/sl, referer: http://www.sitename.com/sl/tractor/106/new-holland-t4050-deluxe [tue may 21 03:16:44 2013] [error] [client 193.189.190.66] file not exist:     /home/162175/domains/sitename.com/html/sl, referer: http://www.sitename.com/sl/tractor/106/new-holland-t4050-deluxe [tue may 21 03:16:44 2013] [error] [client 193.189.190.66] file not exist: /home/162175/domains/sitename.com/html/sl, referer: http://www.sitename.com/sl/tractor/106/new-holland-t4050-deluxe 

i have checked , page not contain dead urls (google chrome extension check links).

what problem?