Hi Richard
Upon upload of memories, many memories (but not all) have the IPO and ATT conditions set even on broadcast FM band, aircraft band, 144 & 450MHz.
Please file a bug with detail to reproduce the problem and an image file on http://chirp.danplanet.com/projects/chirp/issues/new I'll take care of this next monday.
From the front panel, neither of these bits are allowed on 144 or 450MHz. Since the IPO button is disabled above 6m, the IPO cannot be turned off, so presumably the ATT is also set as it is for 6m and below.
For 6m and down, either the IPO or the ATT bit is allowed but not both.
You are right, this is the way ft857 and 897 work. During development I discovered that setting those bits in invalid combination is safe, I mean it does not brick the radio in any way, maybe they are ignored but they are harmless. This is why I decided not to limit user actions here. If you have indication of any harmful effect please let me know.
Tnx 73 de IZ3GME Marco