I've been trying to clean up my buy mode by putting things in collections and hiding them in the catalog but it doesn't seem to be working.
I've used SimPE to open the mesh file and then unticked all the 'function sort' buttons and changed the room sort to 'misc' yet the the items still show up in the catalog. I've even tried it with the categorizer yet still no change. I have no idea what I am doing wrong/missing so any advice would be really appriciated.

TIA

Did you click "commit" after unticking the boxes?

Yeah and then saved it. Its really confusing because I did this a while back and it worked fine but have since redone my downloads folder.

If the objects you're modifying are multi-tile objects, you might be modifying the wrong OBJD - you need to modify the master OBJD, which is the one with the Multi-tile sub index set to 0xffff.

Are you sure you have the edited file in your downloads, and that it's the only copy of that object? And are you deleting groups.cache after adding the fixed object?

Yup, it all looks like it should work fine, but no luck

Please don't just reply "yup it all looks fine". Answer to the specific things, "Yes I deleted groups", "Yes I edited the OBJD with Multi-tile sub index set to 0xffff", so that we know for sure you read and understood the suggestions. Can't help you track it down if you don't give detailed information.

Apologies, yes I deleted the groups and checked that the OBJD I edited was the one with Multi-tile sub index set to 0xffff but still nothing unfortunatley.