Mail about select

Dear Friends,

I have two tables

1. "Radius"

Table = radius
+----------------------------------+----------------------------------+-------+

| Field | Type |
Length|
+----------------------------------+----------------------------------+-------+

| uname | char()
| 256 |
| logdate | date
| 4 |
| logtime | time
| 8 |
| duration | int4
| 4 |
| status | char()
| 20 |
| nasadd | char()
| 20 |
| port | int4
| 4 |
| bytesin | int4
| 4 |
| bytesout | int4
| 4 |
| packin | int4
| 4 |
| packout | int4
| 4 |
| misc | int4
| 4 |
+----------------------------------+---------------------------------

2) "radiustemp" with the same structure
now i am firing a query like this:

select r.uname from radius r, radiustemp rt where r.uname<>rt.uname and
r.logdate<>rt.logdate and r.logtime<>rt.logtime;

After some time i get response
"Segmentation Error"
core(sumped)

can any one help what is the error in this query.

Thanks in advance for your kind help.
Regards,
Vikrant