There was a similar thread not long ago, in which the poster initially expressed mistrust in using the PRNGs provided by Linux and MS Windows to generate private keys. As in your case, it turned out that the concern was not some supposed design flaw in the cryptographic PRNG, but rather that it takes time for a freshly-installed system to seed itself with enough initial entropy. One thing you could do is simply to do random things with the mouse and keyboard and wait a while before generating important keys (the OS's estimate of "entropy available" is only a rule of thumb of course, but certainly at the very least that long). Another is to note that on Linux you can write to /dev/random to feed it entropy from an external source, so if you want you can pipe in an image of a lava lamp, radio static, electronic noise from the CPU, etc.