Can't Select Objects?

I'm using P&ID 2010.

I started work on a P&ID yesterday. It's a drawing of a cooling tower & associated systems for a power plant.

I got about half done yesterday, and then I stopped being able to select anything for editing or changes. I called it quits for the day, and figured it was just a transient instability that would be resolved when I started the software again. Well, when I came back to finish it this morning, the problem is still there. I can add new items, and they're still selectable and editable, but nothing that I did yesterday is accessible. This is a problem because I noticed a couple errors in what I did yesterday, and I've got to fix those, and of course there's still stuff that I need to add.

I've checked the layer browser, and everything is unlocked. I'm not sure where to go from here, though - I'm still pretty new at this software. Anyone have any ideas?

Edit: I just saved this as a copy, and the copy appears to be fully editable now. I'm not really too sure what happened, though ... The original is still locked down.

Bishop,

The first thing to do is make sure you have the latest service pack for AutoCAD P&ID.

http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=13917718&linkID=11705366

Sometimes you can remove the drawing from the project and then add it back to the project to fix this problem.

Also there is a project Audit that can be preformed.

I hope this helps.

I have been seeing this issue lately as well. Though I am using Autocad P&ID 2011. I made a post about it here but really haven't gotten a firm answer. I have found that double clicking on a component will "unlock" it sometimes. Hope that helps?