I worked with the poi-3.0.1-FINAL-20070705.jar and the poi-3.0.2-beta1-20071204.jar. I had the problem that the created files with HSSF crashes Excel 97 when I tried to open this files. With the old poi-2.5.1-final-20040804.jar everthing worked just fine, apart from the problem with the java.lang.outOfMemmory exception when amount of the rows written by HSSF exceeds about 3500 rows. The new versions crahses Excel 97 if the user has no write authorizations on the specific folder.
You could argue that excel shouldn't crash no matter what file you feed it If the same file opens fine in other versions of excel, then you'll probably be best off reporting a bug to Microsoft
Without a response or further information, I am resolving this as "INVALID"
application crash
If you are really having problems with Excel 97 and an outdated version of POI, I suggest you update either. Otherwise, please do not reopen ancient bug reports without providing any new information.