I've been noticing this happening with 64bit users a lot.
Well instead of injecting on login, open your task manager, and go to the processes tab. From there, you want to keep track of when crossfire opens, the moment is opens, then you want to inject there. E-Ject is a good injector, but I recommend you try out other injectors to. Also try out other hacks other than GM Coders, since there are tons of more hacks available.