also, remember Palps never really comes out and says, 'Plagueous was my master, i killed him after he tought me all he knows? Oh, hey want me to teach all that stuff to you and then you can kill me?' so is it not possible that he pushed the time of the story back? besides, an anecdotal story like that that takes place long ago serves Palpatines purpose better than, 'About 10 years ago, my master....'
Its possible that Plagueous created Anakin without Palpatine knowing, so when Palps killed Plagueous the knowledge of Anakin's origin died with him. Palps may have put 2 and 2 together if he knew that Anakin was 'fatherless' but as far as we know, not even Anakin is aware of this (we can only confirm that Shmi and Qui-Gon know this if im not mistaken)
the planet isnt necessarily random/remote to Plagueous, and if he died before Anakin was born then it makes sense that he wasnt by Plagueous' side all his life. If that is how it played out, im sure once he was born, Plagueous would have taken Anakin to train.
and remember, the Force has its own agenda so to speak, there are lines in the OT about it 'guiding us' and bringing people together and stuff like that, so it simply (or could have) guided Qui-Gon et al to Tatooine to find Anakin.
-Darth Simon
ps, i added some comments to my previous post about Anakin being appointed to the Jedi Council, so glance back up there if you read it before then.