internal server error 500 when running installation

hey everybody,

when I install dhtmlxspreadsheet with oracle connection (oracle working) I get a blank page after install (as described in description). oracle is working and all parameters okay and no errors.

when debugging with firebug I get:" network error: 500 internal server error - … /index.php"

all files are 777 and correct user/group.

php installation is working too without problems.

any ideas?

additional information:

no database objects get created, but oracle connection is working, user/pw, sever/port, db correct
db user has right to create tables, index, etc.

then when running install folder gets removed, error in data.php with internal server error 500.

anyone with a solution?