2006-08-18: Battery Recall Program for Dell Notebooks
"From the Dell page: Dell has identified a potential issue associated with certain batteries sold with Dell Latitude™, [...] and Dell Precision Mobile Workstation™ notebook computers. [...] Under rare conditions, it is possible for these batteries to overheat, which could pose a risk of fire."
Please check your battery. Detailed instructions are found here: https://www.dellbatteryprogram.com/
For linux users, there's a script available to ease the first step of identifying affected models:
On an SL4 notebook, it will tell you whether or not any of the batteries in the device is potentially affected, by comparing the model number found in the ACPI information against the list from the URL above. It probably works on other linux flavours as well, and should at least tell you if it fails.