When certain users have tried to upgrade their modem cards to the v.90 standard, the upgrade either stalled at around 10 percent completion or simply "fried" their modems, according to BugNet.
Users who experience the latter scenario are not able to operate their modems even though Windows applications recognize it.
3Com pledged it will exchange a new v.90-configured modem card for any unit destroyed during the process.
A 3Com spokesman told CNET's NEWS.COM that the company is addressing the problem and that tomorrow it will remove the download link from its Web site until the problem is resolved.
The company said the incidence is rare, but urged modem users to take precautions when performing the flash upgrade--a software upgrade of read-only memory in PC hardware.
For example, users should not interrupt the transfer of data when downloading the upgrade, which can occur if the PC enters the "sleep" mode or runs its screensaver. Antivirus software can also interrupt the transfer and should be turned off during the flash upgrade.