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?