LPC932 - ISP entry using external crystal

[Dave]

I am using LPC932 with external crystal - 3.6864MHz. I can access ISP mode using Flash Magic using basic routines using the internal RC clock. Access works on both "break" detect and 3 pulse reset mode. The same software (with the exception of BRG0, BRG1) will not access ISP mode when the external crystal is used. Software runs OK & data is received OK as the software echoes any character sent. The "break" detect is cleary received but simply causes a CPU reset & re-starts the software.

The 3 pulse reset will also not access ISP. User S/W is re-started.

Any clues