Hi - me too. Tried a completely clean install of 1.90+, and yet surveys time out in what I believe to be times between 10 and 20 minutes.
Session life set to 36000 in Limesurvey, memory_limit = 128M, send.session_path pointing to a valid and writeable directory, max_input_time = -1.
Browser cookies and scripts showing expiry of 4 hours after entering site.
I assume that there's something I need to change in php.ini, but struggling to find out what.
Have got debug set to 1 in conf.php, but no errors being written to script log from this.
Any guidance much appreciated - the software is so good, and it's such a shame that I can't use it until I've fixed server side stuff. At least it sounds like other people have got similar problems.