[horde] problem with horde

[mrinal joshi]

hi everyone,
i hv posted my problem earlier too.
my red hat 9 system works properly with horde - imp- turba. but now i started facing one problem that some of the pages like passwd, turba are not replying as blank page in browser and some links like options, folders are trying to open the file rather than excuting it. i hv checked the log files of horde. it has nothing in it. but apache log says segmentation fault,

i also have installed php accelerator so it says in log that phpa.shm_user is not created so cache can not be created.

please help.
is it the problem of php or something else?