smart - hard drive pending sector count

For some reason, my pending sector count to be remapped is unbelievably high (2163 currently). I've seen it go up 20 in one week. But no sectors have been remapped. Dell's computer diagnostics utility reported no problems, smartctl -H returned PASSED, and I have yet to notice any problems with the hard drive.

So do I need to worry about such a high pending count?

Here are the results of smartctl -A:

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000f   100   100   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0007   252   252   025    Pre-fail  Always       -       2062
  4 Start_Stop_Count        0x0032   097   097   000    Old_age   Always       -       36147
  5 Reallocated_Sector_Ct   0x0033   252   252   010    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   095   095   000    Old_age   Always       -       3261
 12 Power_Cycle_Count       0x0032   098   098   000    Old_age   Always       -       2087
191 G-Sense_Error_Rate      0x0032   002   002   000    Old_age   Always       -       999999
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       47
194 Temperature_Celsius     0x0022   127   094   000    Old_age   Always       -       37 (Lifetime Min/Max 13/48)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       191990
197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       2163
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       19080
199 UDMA_CRC_Error_Count    0x0036   252   252   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x000a   252   252   000    Old_age   Always       -       0

Edit:

The disk is about 1 1/2 years old. Pending Sector Count was about 2000 when I started keeping an eye on it 2 weeks ago. I have never noticed any problems with the disk. If it makes any difference, I have a Dell M1530 dual boot Vista-Ubuntu. The hard drive is a Samsung HM160HI.

Edit:

Apparently half the problem was that I didn't (still somewhat don't) know how to interpret the data.

Thanks to everyone who gave me feedback.

Answer

Your Current Pending Sector Count (2163) is higher than the Reallocation Sector Count (252).
This means that failing sectors can no longer be replaced by the disk firmware.
The disk is failing - make sure you've backups, and get a replacement..