undefined symbol: __log1p when trying to load libphp4.so

I recently tried to upgrade PHP from 4.0.6 to 4.1.2 on a Cobalt RAQ3 server running RH 6.2 All apeared to go well through the configure, make and make install but when I tried to start apache I got the following error Setting up Web Service: Syntax error on line 33 of /etc/httpd/conf/httpd.conf: Cannot load /usr/lib/apache/libphp4.so into server: /usr/lib/apache/libphp4.so: undefined symbol: __log1p /usr/sbin/httpd I even tried 4.1.1 but got the same error. I "borrowed" libphp4.so (4.1.1) from a freind's RAQ server and got thing running again. As I understand it log1p is somthing to do with floating point numbers within PHP Any one seen the same problem or got any suggestions Thanks in advance Dave Trevallion