All testing by the community so far leads to the issue being account side on EA/Maxis' end.
In each of the following cases, an account unaffected by Error 73003 was tested and was able to log in.
Known to have no effect:
Assuming that Error 73003 can affect players attempting to play the demo, players should download the Demo before purchasing Darkspore and should check that they can play the demo on their account. If they cannot, they should create a new Origin account and attempt to log into Darkspore with that account when playing Darkspore. This process should be repeated until an account is not affected by Error 73003. The player should then purchase Darkspore for this account.
A number of players have talked about how they have contacted an EA Game Advisor complaining about being affected by this error. A lot claim to have received money off of other games and in some cases, full games of similar value when trying to obtain a refund for their purchase. These claims cannot be confirmed however.
Known graphical glitches include: