Help with Consistency errors

[Vox]

Hi, I just joined the group, I've used Eagle for years on hobby projects. I just completed a schematic and board. Autorouted it with some manual intervention. All was good. Then i decided to add a led and resistor and consistency went from bad to worse. I don't want to autoroute it again and i've read all the many internet posts on fixing consistency errors, but nothing fixes mine.

Even more frustrating I tried the netscript to get harmony and it decided to airwire my extensive ground tracks to some signal tracks and I couldn't edit the airwires even though the sch wire nets were correct. A screen pops up 'connect this Net with another,' but doesn't have the option to say no leave them alone! The last big hole was I decided to delete a TL074P 14pin DIL from the sch and brd and re import from the same library. Now every pin on the IC  errors with 'Different connections on IC1A pin X  and pad y (N$21.none) etc for each pin.

I can export a netlist from the sch. and connections look fine. If I rename the brd file and just run the sch. I can produce a new board without errors but it's not autorouted. I have been mixing imperial and metric grids and mirrored some ICs on the schematic and I'm wondering now if either is part of my problem. Eagle was designed for mostly imperial parts on a 0.1" grid, but now I use both imperial and metric parts.

I've nearly given up in frustration trying to get rid of these IC pin and pad 'Different Connections'. I'm also seeing some pads on the brd with no visible airwire, even though they connect on the sch and i can show or move the part and connected wires move with itDoes anybody know how the ERC file is formed and compares the sch with the brd? I'd like to compare my sch netlist with what the ERC is finding wrong on the board when it runs. If I can see what's wrong, editing those files with a text editor for consistency or deleting board components might solve my problem?

Thanks