If you have two web sites on a single server and differentiate them by port only, i.e. http://DevBox:8001 http://DevBox:8002 then their cookies end up in the same file as stored in C:\Documents and Settings\YourUserName\Local Settings\Temporary Internet Files\

 For example, here is Cookie:me@devbox

CONDECOLOGINTRANSLATE
LangLogin=1
DevBox/
1024
1550712832
30050933
2300552288
29984472
*
RequestState
Saved=True&DeskChecked=True&DeskApproved=True&Completed=False&Allocated=True&Rejected=True
DevBox/
1024
1068875776
30039869
4055943584
30002971
*
UAT_OARs
WZ/69JEzyO3RfCIivkPOL7eqw5++X8msgmQzRSCJkIR+o3zQlkKUJZoO4fhdrNVY
DevBox/
9216
2150554368
30003992
1320443552
30003988
*

This is fine unless they have different expiries, as IE seems to wrap the enitre file up with the same expiries.