Unrecognized Battery 6340

HI new to this site and HP IPAQ ,just bought a 6340 that needed a battery,so got aftermarket battery "compatable" but when i try use it it says an unreconized battery has been detected ,then it discharges the battery ect,is this a comon thing or a faulty battery or is there a patch to get round this ..any herlp please,the place i got the battery from will exchange it if i want as thay have never had a problem? i also tried a new wall charger hoping the detection of the battery was in the desk charger but nope,desprate to get this working ,not just when plugged in to the mains ..cheers Alistair the newbie kennington..

OK HERE IS THE FIX FOR THE UNRCOGNIZED BATTERY PROBLEM...
contackted hp ipaq online fixer chat thing... was told after trying loads a stuff the following & please i know it sound like a load of doggs dangly bits but it worked so .. (1) plug fone into charger ignore the message saying unrecognized battey.
(2) charge for 4 hrs,even though it is not actualy charging
(3) dead on 4 hrs unplug it and remove the battery.
(4) please ensure you leave the battery removed from ipaq and ipaq removed from charger for 24 hrs .
(5) put battery in,put charger in "DA DA" all fixed? strange but true..
this question is all over the net with no fix so now here is the fix for it..