Yes...We found a bug in the registration system (how it came about I'm not sure), whereby the post-1st July fee became active, and the current one inactive.
Net result: If you edited your details (e.g. to upload the picture for your conbadge) before I fixed that little problem, you got "upgraded" to paying the higher amount! I did, however, fix all of those that were affected.
leinir is currently working on a fix so the same thing doesn't happen for existing members come 1st July (or thereabouts) when we introduce the higher pricing.
Cheers,
Southie