Thanks to all for the inputs.

I have not yet taken the cassette off. However, it looks like the chain is seating OK (visually, anyways).

I'm using the lock ring that came with the new cassette. I do still have the old IG-60 cassette so I may see if that lock ring makes any difference. The spacer issue was also something that crossed my mind, but not very seriously. I also used the spacers that came with the new cassette. I'll pull out the old cassette and compare spacing between the new and old and see if/where there are any differences and make any adjustments.

When I installed the IG-60 (the one recently replaced by the HG-30) a few years ago, I had no problems at all with it (same gearing, 11-28, as this new HG-30).

One correction: In an earlier posting, I stated that I had replaced the chain and then replaced the cassette because of slippage. That's actually the other way around. I replaced the cassette first, then realized I needed a new chain

As mentioned previously, I'll post back what I find. Should get to the bike in the next day or so.

Thanks again and cheers...Steph