With so many technical difficulties plaguing Spore I thought it may be a good idea to post up some solutions since I had some and found them incredibly frustrating. Hope it helps...
Starting Up
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1)Make sure your PC can run the game at all since the requirements are genreally overlooked. Just to make sure, use this site. Link->
Can You RUN It?
2) Apparently the EA Download Manager can prevent Spore from starting up so if it asks you to install it, don't do it at all. If you already have it installed, get rid of it. If that doesn't work. Uninstall Spore and EADM then reinstall Spore but not the EADM.
3) Running the game under Compatibility Mode under Windows 95 *may* work. Right click the Spore icon, then the Compatibility Mode, tick the box and choose Windows 95 from the drop down menu.
4) Cleaning up the hard drive and registry may also help. Use C-Cleaner to do this. Link->
CCleaner - Update . Handy for general maintenance as well anyway.
5) Uninstall the Creature Creator aswell! Don't worry about your creations, they left well alone.
Crashing
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1) If the game crashes/freezes from time to time it may be your graphics drivers (or soundcard/motherboard). Make sure to update to the latest ones.
For nVidia users;
Drivers - Download NVIDIA Drivers
For ATi users;
Drivers & Software
If crashes/freezing still occurs try using the Omega drivers;
OmegaDrivers.net - Home of the ATI & NVIDIA Omega Drivers. Drivers Main Page (For both nVidia and ATi).
Uninstall your current drivers before installing these.
NB: The Omega drivers stopped the crashing for me but I'm getting weird graphic artifacts. Their uncommon though.
2) If your graphics card is over heating try lowering the graphical settings and/or increase airflow to the computer by buying better fans and placing the computer in a more aerated space.
3) If your computer is over clocked, try reseting the computer to it's default factory status. Some games have been known to be very sensitive to over clocking (such as TES 4).
Others
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1) Logging in to your account (as of now) isn't very likely to happen as EA are having problems (not surprisingly

) with servers. Some people are having problems with validating thier account. The option to resend the validation e-mail is no where to be found so far though.

Check your spam filter or your junk folder to see if it's there. Also, supposedly Hotmail doesn't really work with the validation mail so it may worth using a different e-mail account (G-Mail for example).
2) Spore is a big game (about 6GB I think), so defragmenting your hard drive might reduce stuttering.
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So far these are solutions I've found. Any more are welcome. Sharing is caring people!