I'm assuming that you tried a compact and repair.
Are the weird symbols in a memo field? If so, here's what to try.
1. Make a complete backup of the database mdb file(s) and put away for safe
keeping.
2. Create a query that excludes the particular problem record. Include all
fields or use the * wildcard. You need a primary key for this to work so that
you know exactly which record. An autonumber field is best if you don't
already have a PK. After running the query to ensure the proper records are
returned, change it to a Make Table query and run it.
3. Next change the query back to a Select query. This time only search for
the problem record. Make sure that all fields show EXCEPT for the problem
field. Run it to make sure. Then change the query to an append query and
append the bad record to the table that you just created.
4. Delete the corrupt table. Rename the new table with the same name as the
old one. You might have problems if there are relationships involved.
5. Create a new database and import everything from the old database. Use
this DB in the future.
Tony Toews has an excellent web page on database corruption.
http://www.granite.ab.ca/access/corruptmdbs.htm
Allen Brown also has excellent info on corruption.
http://allenbrowne.com/ser-47.html
I have a white paper in a Word document named Fix Corrupt Access Database
towards the bottom this page:
http://www.rogersaccesslibrary.com/OtherLibraries.asp