from isa to pci slows down sound

I have a v-thin computer (under 2.5 inches) and am therefore tightly constrained as to which sound card I can use.
I have been using an old OPTi plug-and-play mpu 401 card,
which is isa - and powerful enough to drive speakers alone.
My Joystick port gives intermittently bad readings (planes crash), so I decided to upgrade. I bought an Avance Logic als4000 equipped cheap sound card.

Problem - I can install the new card without problem - but in
games such as Quake 3 there is now a delay between action and sound ( even the opening crashes are delayed by a fraction).
The delays are also in Quake 2, but running Quake 3 they can be 1 second.
I re-install the isa card and everything works perfectly.

The motherboard is a QDI advance 10 - about a year and a half old.
The processor I am running is a 1.3 G Celeron. I am using Win98.

Can anyone give me pointers as to a fix ?????

Have you tried putting the sound card in a different PCI slot? It may be conflicting with another device, even though it says it's working propely in the device manager.

mmm --

i'll get out the screwdriver and report back

well - no change -

- but more info.
dxdiag reports all forms of sound acceleration as failed
- so I try for the newest driver 10-12-2001

still - only "no acceleration" works.

so - is this normal for an als 4000 card , or
did I buy a PUP . (Maplin £9)

Thanks for the suggestion



Edit.
OR can anyone suggest a sound card that is
about 1.5 inches high (or modded to such) and works
smoothly.....