In addition to what Ofer said to look for, click on the "All" tab, and look
at the recordsource. Does it specify a table name, or do you see something
like "SELECT * FROM ... " If so, click the the button directly to the right
[...]. This will open the query builder. Is there only one table showing in
the pane, or are there two or more tables with lines connecting them? If you
only see one table or query listed, then you'll have to look elsewhere. On
the same tab of the form's property sheet, look for ALLOW EDITS, ALLOW
ADDITIONS, DATA ENTRY, etc...
The attributes should be:
Allow Edits = Yes
Allow Additions = Yes
Allow Deletions = Yes
Data Entry = No
If that doesn't solve your problem, then click on the "Events" tab. Are
there any listed events with [Event Procedure] on the line? If so, click the
ellipse button [...] to open the vba editor. Look for anything that has
either an .Enabled or .Locked reference.
Brian