|Problem: Your subclass of Object used to say something like this in its copy method:
id aCopy = [super copy];
which resulted in:
Mar 23 06:10:09 CheckSum
*** -[SplitTransaction copyWithZone:]: selector not recognized
Solution: Create the object right there and then:
id aCopy = [[MYOBJECT allocWithZone:[self zone]]init];
Problem: In 3.x, you maintained your strings file in an NXStringTable within IB, but when you try and view the strings under 4.0, you get this message:
Runtime error: NXStringTable: does not recognize selector -inspectorClassNameForMode.
Solution: Under 3.x, open the .nib file with the strings, bring up the Strings inspector, and export the strings to <NAME>.strings. In 4.0, just add this strings file to your *.lproj directory under "Other Resources" category of PB.