I'm using an Analog Devices microconverter with an 8052 core for a project
Would it be too difficult to give the actual name of the chip?
Your problem sounds like timing.
1) Grab the datasheet of your uC and your memory after you have made sure you know ALL the numbers of your chips and see that all timings are met at your crystal timing. If your crystal is in a socket, this can be checked very easily by poppin a slower crystal in (remember to - temporarily - change the UART timer values).
2) Verify that the ALE latch indeed latches
3) some uC/RAM combinations seem to work better when you put 10k pullups on P0.

Erik