So I've got a 486-project on-going and I decided to post this question as a separate thread in the event its a known issue or misconfiguration.

The card in question is SoundBlaster 32 (CT3670).
The symptoms as I observe them are:

- Card resources are successfully set during boot and the card is working, until the system has sat unused (as in no audio playback)
- If I start a game after the card has disappeared, no sound card will be found and running DIAGNOSE.EXE will report that the resources for the card cannot be set.
- If the card is working and I leave a game to sit in a quiet spot (for example, there are portions of Monkey Island when no audio is present), sometimes resuming playback the FM synthesis sounds really weird - it is completely tonally off. After exiting the game and restarting I only get PC-speaker.
- Seems intermittent, but so far has not occurred mid-operation. The card only goes missing or starts acting up if it's not being utilized for some period of time.

After the card is probed once or twice, as I run DIAGNOSE.EXE again, the card resources are re-established and it starts working again.

The most recent change to the system that I made was that I connected a AAA-battery compartment to the external battery header on the motherboard:

I can't say for certain if the problem was present before I did this, but I am fairly certain it was not. The system now keeps time and CMOS settings between reboots and being disconnected from the wall outlet.

Prior to adding the external battery, I also added a 3Com Etherlink III ISA 3C509B-TPO.

The sound card does appear properly inserted all the way and the slot was not changed when the battery compartment or ethernet card was connected.

Could there be a BIOS setting that the card does not like - or a conflict with another ISA device? Or is this likely to just be really old hardware acting up and I just need to unseat and reseat the card(s)?

Could the external battery be screwing with the motherboard function in some way?