Ok... This is what I did......

- Starting from a clean hlds_l install, I updated it to latest version (using ./steam -update)
- Installed RealBot v1.00 as per the Readme and it worked fine
- installed metamod and changed liblist.gam to load metamod (and not realbot) and metamod worked fine (obvously at this stage realbot was not loaded)
- changed command line for launching hlds from
./hlds_run -game cstrike
to
./hlds_run -game cstrike +localinfo mm_gamedll dlls/realbot_i486.so
- metamod works fine and so does realbot

As Metamod works fine with realbot, I would assume that if you then load a metamod plugin that causes the server to crash, it is most likely the plugin that is at fault.