Service Pack 1 for Internet Explorer 5.5 is released and available at http://www.microsoft.com/windows/ie/download/ie55sp1.htm.
The list of fixes include:
Q268976 - Internet Explorer Window Closes When You Click a Download Link.
Q268772 - BUG: onload Event Does Not Fire for Active Desktop.
Q267991 - BUG: "Content-Disposition: Attachment" Fails for Known Content Types.
Q266121 - Internet Explorer Always Retrieves from Transparent Cache Servers.
Q262208 - AutoConfig .pac File in .ins File Is Not Associated with DUN Connection.
Q259827 - Intermittent "Application Exception" Error Messages in Internet Explorer.
Q259365 - Memory Leak in Internet Explorer Default Download Behavior.
Q258141 - Host Logic in PAC File May Not Direct Browser to the Intended Proxy Server.
Q256344 - Internet Explorer Problems When RAS Services Are Disabled.
Q218933 - Custom User Agent String Not Sent by IEAK Wizard for Automatic Version Synchronization.
Q151271 - XL97: Error Dragging Excel File into Internet Explorer.
NOTE: Service packs are cumulative, so issues that are fixed in this service pack will also fixed in subsequent service packs.