Howto build 32bit apps on amd64 suse 9.3?

Hi all, I am trying to compile syncekonnector-0.2.1 on a suse 9.3 amd64 platform. It depends on synce and synce-devel packages with are both (to my knowledge 32bit packages. configure complains about de synce libraries not being compatible in config.log. So, I instructed configure to use 32bit compile (-m32). Now, it complains it can't find libXext, but I know it's there (devel packages are both in 64bit and 32bit present). I'm not a devel guy, who to get out of this mess?