As previously reported, Apple's action follows a growing number of problems users are reporting with their Mac OS 8.5 upgrades, glitches that are relatively isolated but significant and not fully understood.
The problems with Mac OS 8.5 initially appeared to be limited to users who had previously formatted their hard drives with third-party tools or different operating systems. The glitch results in data loss in some cases.
But now different and more varied symptoms are cropping up, according to reports posted on the widely read MacInTouch and MacFixIt Web sites. Among the problems are files and desktop folders that disappear even though the data in them can still be found.
Based on the user reports, the problems seem to affect a limited number of users, yet don't seem to be linked to the use of any particular hardware or software configuration. Also, the problems may not occur until after several days of use, according to MacInTouch's Ric Ford.
"We think OS 8.5 is of excellent quality, but we take these reports seriously. We will communicate to customers any information we find" on reports of problems, Apple spokesperson Russell Brady said.
Former Mac clone maker Umax posted a warning on its Web page, suggesting that "users hold off on upgrading mission-critical systems to Mac OS 8.5 until this issue can be conclusively isolated and addressed."
Consumers also report that the software isn't being supported by Apple for use on Mac clones.
Umax technicians have been able to recreate the problem but have not determined any root causes. The company suggested that the problem "will probably affect only an extremely small number of users--but to those users, its impact may be severe."
Some alleged bugs have affected the Sherlock search function of the new OS as well. Sherlock is a new feature of Mac OS 8.5 that searches hard disk drive files and several different Internet search engines simultaneously.
Some who have tried the feature say that Sherlock will occasionally fail to work properly when their Internet connection passes through a proxy server. In this situation, error messages may be returned instead of search results.
The alleged bug was first reported by Mark Kriegsman, president of ClearWay Technologies. ClearWay makes a standalone product for Macs and PCs that, like Sherlock, is used to search multiple Internet sites at a time.
Users connected to corporate networks are most likely to be affected by the Sherlock problem, because companies often replicate frequently used Web pages on a local server to improve security and access speed. A relatively small number of home users would encounter such problems because their service providers typically aren't hosting content on local servers, and not all types of proxy servers are affected.
Apple recently posted information on its support site offering ways to reconfigure Sherlock, but readers report that the bug persists even after the changes are made.
"We have a network with six Macs [and five PCs] that we updated to OS 8.5 and none of them can do an Internet search using Sherlock even with the right proxy settings. We can use a browser to access the Internet, so we know that the problem lies within Sherlock," said Jeff Schatz, an employee in the creative department of WinBook Computer.
Schatz further reported that none of the systems have had any hard disk problems.
A spokesperson for Apple said the company is looking into the matter but has not confirmed that a problem exists with the search function.
It is not uncommon for new software to have problems, and the Mac OS is no exception. After the launch of Windows 98, Microsoft had to fend off a flood of users complaining about bugs after installing the software.