Postgres 9.2.4 "Double Precision" Precision

I recently upgraded from postgres 8.2.6 to 9.2.4 . For the most part I am
enjoying the upgrade. I have found one behavior that I can not explain.....

Below is sample contents of a table. "VALUE" in column 7 is defined as
double precision (table definition is the same in 8.2.6 as 9.2.4).
The change over from 8.2.6 to 9.2.4 happened after 2013-09-10 16:00:00.

In postgres 8.2.6 a value inserted , 6.31, is represented in the database
as 6.31 (7th column,7th row)
In postgres 9.2.4 a value inserted , 6.32, is represented in the database
as 6.32000017166138 (7th column, 6th row)

VALUE
SLMO3 | HG | 0 | RG | Z | 2013-09-10 18:15:00 | 6.32000017166138
| Z | 1879048191 | 0 | MSGPRODID | 2013-09-10
20:02:00 | 2013-09-10 20:03:15
SLMO3 | HG | 0 | RP | Z | 2013-09-10 18:15:00 | 6.32999992370605
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
19:15:00 | 2013-09-10 19:15:34
SLMO3 | HG | 0 | RP | Z | 2013-09-10 18:00:00 | 6.32999992370605
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
18:18:00 | 2013-09-10 18:18:12
SLMO3 | HG | 0 | RP | Z | 2013-09-10 17:45:00 | 6.32999992370605
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
18:18:00 | 2013-09-10 18:18:12
SLMO3 | HG | 0 | RP | Z | 2013-09-10 17:30:00 | 6.32000017166138
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
18:18:00 | 2013-09-10 18:18:12
SLMO3 | HG | 0 | RP | Z | 2013-09-10 17:15:00 | 6.32000017166138
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
18:18:00 | 2013-09-10 18:18:12
SLMO3 | HG | 0 | RP | Z | 2013-09-10 16:00:00 | 6.31
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
16:18:23 | 2013-09-10 16:18:23
SLMO3 | HG | 0 | RG | Z | 2013-09-10 16:00:00 | 6.28
| Z | 1879048191 | 0 | KWOHRRSPTR | 2013-09-10
16:16:32 | 2013-09-10 16:17:33
SLMO3 | HG | 0 | RG | Z | 2013-09-10 15:45:00 | 6.28
| Z | 1879048191 | 0 | KWOHRRSPTR | 2013-09-10
16:16:32 | 2013-09-10 16:17:33
SLMO3 | HG | 0 | RP | Z | 2013-09-10 15:45:00 | 6.31
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
16:18:23 | 2013-09-10 16:18:23
SLMO3 | HG | 0 | RP | Z | 2013-09-10 15:30:00 | 6.31
| Z | 1879048191 | 0 | KPQRRR6PQR | 2013-09-10
16:18:23 | 2013-09-10 16:18:23
SLMO3 | HG | 0 | RG | Z | 2013-09-10 15:30:00 | 6.27
| Z | 1879048191 | 0 | KWOHRRSPTR | 2013-09-10
16:16:32 | 2013-09-10 16:17:33

As the values effect arithmetic calculations, I wish the database to
represent values as they are given. For instance, 6.345 would be
represented as 6.345..... 6.3 represented as 6.3.
Does anyone have any suggestions?

Thanks in advance,
Joanne