So far Opera 10.5 is only in MSI format. Granted it's early yet, but it seems extremely likely that Opera itself will still work fine on 98SE as it always has. Most likely just the MSI is incompatible with 98SE. Encourage Opera to be proper and release a non-MSI distribution or allow third-parties to release a 98SE-compatible release (taken out of the MSI wrapper) so the Opera 10.5 will be available for 98SE. Just a general rally call